SetSite failed for the package [GitHubPackage], VS 15.8 Preview 4/5

[vaindil]

This is a dupe of #1625 but the problem just recently started happening for me. GitHub extension is 2.5.4.3349. I'm on VS 2017 Professional, currently on 15.8 Preview 5. I believe the problem also happened with Preview 4. I get a popup error message every time I open a solution that uses git, whether it uses GitHub or not. The log is below.

<entry>
  <record>915</record>
  <time>2018/07/27 19:48:11.911</time>
  <type>Warning</type>
  <source>VisualStudio</source>
  <description>Unexpected system error mode before loading package [GitHubPackage]</description>
  <guid>{C3D3DC68-C977-411F-B3E8-03B0DCCF7DFC}</guid>
</entry>
<entry>
  <record>916</record>
  <time>2018/07/27 19:48:11.911</time>
  <type>Information</type>
  <source>VisualStudio</source>
  <description>Begin package load [GitHubPackage]</description>
  <guid>{C3D3DC68-C977-411F-B3E8-03B0DCCF7DFC}</guid>
</entry>
<entry>
  <record>917</record>
  <time>2018/07/27 19:48:11.953</time>
  <type>Error</type>
  <source>VisualStudio</source>
  <description>SetSite failed for package [GitHubPackage]Source: &apos;System.ComponentModel.Composition&apos; Description: No exports were found that match the constraint: &#x000A;&#x0009;ContractName&#x0009;GitHub.Commands.IOpenFromUrlCommand&#x000A;&#x0009;RequiredTypeIdentity&#x0009;GitHub.Commands.IOpenFromUrlCommand&#x000D;&#x000A;</description>
  <guid>{C3D3DC68-C977-411F-B3E8-03B0DCCF7DFC}</guid>
  <hr>80131500</hr>
  <errorinfo></errorinfo>
</entry>
<entry>
  <record>918</record>
  <time>2018/07/27 19:48:11.959</time>
  <type>Error</type>
  <source>VisualStudio</source>
  <description>End package load [GitHubPackage]</description>
  <guid>{C3D3DC68-C977-411F-B3E8-03B0DCCF7DFC}</guid>
  <hr>80131500</hr>
  <errorinfo></errorinfo>
</entry>

[ManlyBoy]

It's started happening at the same time as yours on mine as well. Vs2017 Version 15.7.3 .

{C3D3DC68-C977-411F-B3E8-03B0DCCF7DFC}

[abhitalks]

It hit me today! Suddenly today I was hit with this error while opening a solution in Visual Studio. Was working just fine until yesterday night.

VS Community Edition v15.6.6
Github Extension v2.5.4.3349

These are the last entries in my activitylog.xml:

  <entry>
    <record>752</record>
    <time>2018/08/01 06:39:39.501</time>
    <type>Information</type>
    <source>VisualStudio</source>
    <description>End package load [RestoreManagerPackage]</description>
    <guid>{2B52AC92-4551-426D-BD34-C6D7D9FDD1C5}</guid>
  </entry>
  <entry>
    <record>753</record>
    <time>2018/08/01 06:39:39.519</time>
    <type>Error</type>
    <source>VisualStudio</source>
    <description>SetSite failed for package [GitHubPackage]Source: &apos;System.ComponentModel.Composition&apos; Description: No exports were found that match the constraint: &#x000A;&#x0009;ContractName&#x0009;GitHub.Commands.IOpenFromUrlCommand&#x000A;&#x0009;RequiredTypeIdentity&#x0009;GitHub.Commands.IOpenFromUrlCommand&#x000D;&#x000A;</description>
    <guid>{C3D3DC68-C977-411F-B3E8-03B0DCCF7DFC}</guid>
    <hr>80131500</hr>
    <errorinfo></errorinfo>
  </entry>
  <entry>
    <record>754</record>
    <time>2018/08/01 06:39:39.524</time>
    <type>Error</type>
    <source>VisualStudio</source>
    <description>End package load [GitHubPackage]</description>
    <guid>{C3D3DC68-C977-411F-B3E8-03B0DCCF7DFC}</guid>
    <hr>80131500</hr>
    <errorinfo></errorinfo>
  </entry>
</activity>

[bambam88]

Just got hit by this message...It was working fine yesterday.

VS Community Edition v15.6.6
Github Extension v2.5.4.3349

last entries in my activitylog.xml

`
916
2018/08/01 14:29:24.557
Warning
VisualStudio
Unexpected system error mode before loading package [PullRequestStatusBarPackage]
{5121BEC6-1088-4553-8453-0DDC7C8E2238}


917
2018/08/01 14:29:24.557
Information
VisualStudio
Begin package load [PullRequestStatusBarPackage]
{5121BEC6-1088-4553-8453-0DDC7C8E2238}


918
2018/08/01 14:29:24.557
Information
VisualStudio
Entering function CVsPackageInfo::HrInstantiatePackage
{C3D3DC68-C977-411F-B3E8-03B0DCCF7DFC}


919
2018/08/01 14:29:24.557
Warning
VisualStudio
Unexpected system error mode before loading package [GitHubPackage]
{C3D3DC68-C977-411F-B3E8-03B0DCCF7DFC}


920
2018/08/01 14:29:24.557
Information
VisualStudio
Begin package load [GitHubPackage]
{C3D3DC68-C977-411F-B3E8-03B0DCCF7DFC}


921
2018/08/01 14:29:24.582
Information
VisualStudio
End package load [PullRequestStatusBarPackage]
{5121BEC6-1088-4553-8453-0DDC7C8E2238}


922
2018/08/01 14:29:24.595
Information
VisualStudio
End package load [InlineReviewsPackage]
{248325BE-4A2D-4111-B122-E7D59BF73A35}


923
2018/08/01 14:29:24.634
Error
VisualStudio
SetSite failed for package [GitHubPackage]Source: 'System.ComponentModel.Composition' Description: No exports were found that match the constraint: ContractName GitHub.Commands.IOpenFromUrlCommand RequiredTypeIdentity GitHub.Commands.IOpenFromUrlCommand
{C3D3DC68-C977-411F-B3E8-03B0DCCF7DFC}

---

80131500



924
2018/08/01 14:29:24.642
Error
VisualStudio
End package load [GitHubPackage]
{C3D3DC68-C977-411F-B3E8-03B0DCCF7DFC}

---

80131500



925
2018/08/01 14:29:24.646
Information
VisualStudio
End package load [Tab Designer Launcher]
{B4E787A4-A9FC-4579-945E-D71AFEC4DD90}

`

[grokys]

@tinaschrepfer does this look like something that would be caused by the VS installer?

[grokys]

Oh actually, i notice IOpenFromUrlCommand in the logs. That's a feature we just added. I suspect this may be caused by an out-of-date MEF cache.

@vaindil @ManlyBoy @abhitalks @bambam88 - could you try clearing your VS MEF cache? https://github.com/Codealike/Codealike-KnowledgeBase/blob/master/clear-visual-studio-component-cache.md

There's also this extension to do the same: https://marketplace.visualstudio.com/items?itemName=MadsKristensen.ClearMEFComponentCache

[vaindil]

@grokys I just cleared my MEF cache, the error still popped up when I reopened VS.

[bambam88]

Clearing the cache did NOT resolve the problem for me. Still seeing the same popup.

[abhitalks]

@grokys The ComponentModelCache folder does not exist in my installation! Have updated the VS to v15.7.5 and the problem persists.

[grokys]

I've tried but I'm unable to repro this here. I don't suppose anyone could try the following for me?

• Run VS and wait for the dialog
• Run another instance of VS and attach the debugger to the first instance
• Open Debug -> Windows -> Modules
• Enter "GitHub" in the Search box
• Select all entries, right-click and copy
• Paste the output here

That might help me diagnose the problem.

cc: @onovotny

[vaindil]

@grokys Is this what you're looking for? Sorry, the formatting is crap, not sure how to make it nicer though.

GitHub.InlineReviews.dll	GitHub.InlineReviews.dll	C:\PROGRAM FILES (X86)\MICROSOFT VISUAL STUDIO\PREVIEW\PROFESSIONAL\COMMON7\IDE\EXTENSIONS\GITHUB\GITHUB\GitHub.InlineReviews.dll	Yes	No	Skipped loading symbols.		110	2.05.4.3349	7/20/2018 4:12 PM	16700000-1673C000	[6980] devenv.exe	[1] DefaultDomain	
GitHub.VisualStudio.dll	GitHub.VisualStudio.dll	c:\program files (x86)\microsoft visual studio\preview\professional\common7\ide\extensions\github\github\GitHub.VisualStudio.dll	Yes	No	Skipped loading symbols.		156	2.05.4.3349	7/20/2018 4:12 PM	1B930000-1B982000	[6980] devenv.exe	[1] DefaultDomain	
GitHub.Exports.dll	GitHub.Exports.dll	c:\program files (x86)\microsoft visual studio\preview\professional\common7\ide\extensions\github\github\GitHub.Exports.dll	Yes	No	Skipped loading symbols.		157	2.05.4.3349	7/20/2018 4:12 PM	1B3A0000-1B3C6000	[6980] devenv.exe	[1] DefaultDomain	
Serilog.dll	Serilog.dll	c:\program files (x86)\microsoft visual studio\preview\professional\common7\ide\extensions\github\github\Serilog.dll	Yes	No	Skipped loading symbols.		158	2.05.0.0	<Unknown>	1B3D0000-1B3F2000	[6980] devenv.exe	[1] DefaultDomain	
GitHub.Api.dll	GitHub.Api.dll	c:\program files (x86)\microsoft visual studio\preview\professional\common7\ide\extensions\github\github\GitHub.Api.dll	Yes	No	Skipped loading symbols.		159	2.05.4.3349	7/20/2018 4:12 PM	1B240000-1B250000	[6980] devenv.exe	[1] DefaultDomain	
GitHub.Logging.dll	GitHub.Logging.dll	c:\program files (x86)\microsoft visual studio\preview\professional\common7\ide\extensions\github\github\GitHub.Logging.dll	Yes	No	Skipped loading symbols.		160	2.05.4.3349	7/20/2018 4:11 PM	1B250000-1B258000	[6980] devenv.exe	[1] DefaultDomain	
Rothko.dll	Rothko.dll	c:\program files (x86)\microsoft visual studio\preview\professional\common7\ide\extensions\github\github\Rothko.dll	Yes	No	Skipped loading symbols.		162	0.00.3.0	12/11/2017 5:00 AM	1B2D0000-1B2FA000	[6980] devenv.exe	[1] DefaultDomain	
GitHub.TeamFoundation.15.dll	GitHub.TeamFoundation.15.dll	c:\program files (x86)\microsoft visual studio\preview\professional\common7\ide\extensions\github\github\GitHub.TeamFoundation.15.dll	Yes	No	Skipped loading symbols.		163	2.05.4.3349	7/20/2018 4:12 PM	1B320000-1B338000	[6980] devenv.exe	[1] DefaultDomain	
Serilog.Enrichers.Process.dll	Serilog.Enrichers.Process.dll	c:\program files (x86)\microsoft visual studio\preview\professional\common7\ide\extensions\github\github\Serilog.Enrichers.Process.dll	Yes	No	Skipped loading symbols.		164	2.00.1.0	2/14/2017 7:12 AM	1B2A0000-1B2A8000	[6980] devenv.exe	[1] DefaultDomain	
Serilog.Enrichers.Thread.dll	Serilog.Enrichers.Thread.dll	c:\program files (x86)\microsoft visual studio\preview\professional\common7\ide\extensions\github\github\Serilog.Enrichers.Thread.dll	Yes	No	Skipped loading symbols.		166	3.00.0.0	11/13/2016 6:03 PM	1B2C0000-1B2C8000	[6980] devenv.exe	[1] DefaultDomain	
Serilog.Sinks.File.dll	Serilog.Sinks.File.dll	c:\program files (x86)\microsoft visual studio\preview\professional\common7\ide\extensions\github\github\Serilog.Sinks.File.dll	Yes	No	Skipped loading symbols.		167	3.02.0.0	1/2/2017 10:29 PM	1B340000-1B34A000	[6980] devenv.exe	[1] DefaultDomain	
GitHub.Extensions.dll	GitHub.Extensions.dll	c:\program files (x86)\microsoft visual studio\preview\professional\common7\ide\extensions\github\github\GitHub.Extensions.dll	Yes	No	Skipped loading symbols.		168	2.05.4.3349	7/20/2018 4:11 PM	1B370000-1B37C000	[6980] devenv.exe	[1] DefaultDomain	
GitHub.UI.Reactive.dll	GitHub.UI.Reactive.dll	C:\PROGRAM FILES (X86)\MICROSOFT VISUAL STUDIO\PREVIEW\PROFESSIONAL\COMMON7\IDE\EXTENSIONS\GITHUB\GITHUB\GitHub.UI.Reactive.dll	Yes	No	Skipped loading symbols.		186	2.05.4.3349	7/20/2018 4:12 PM	10320000-10336000	[6980] devenv.exe	[1] DefaultDomain	
ReactiveUI.dll	ReactiveUI.dll	C:\PROGRAM FILES (X86)\MICROSOFT VISUAL STUDIO\PREVIEW\PROFESSIONAL\COMMON7\IDE\EXTENSIONS\GITHUB\GITHUB\ReactiveUI.dll	Yes	No	Skipped loading symbols.		187	6.03.1.0	7/20/2018 4:11 PM	10960000-109A2000	[6980] devenv.exe	[1] DefaultDomain	
Splat.dll	Splat.dll	C:\PROGRAM FILES (X86)\MICROSOFT VISUAL STUDIO\PREVIEW\PROFESSIONAL\COMMON7\IDE\EXTENSIONS\GITHUB\GITHUB\Splat.dll	Yes	No	Skipped loading symbols.		188	1.06.2.0	7/20/2018 4:11 PM	10360000-10372000	[6980] devenv.exe	[1] DefaultDomain	
GitHub.Exports.Reactive.dll	GitHub.Exports.Reactive.dll	C:\PROGRAM FILES (X86)\MICROSOFT VISUAL STUDIO\PREVIEW\PROFESSIONAL\COMMON7\IDE\EXTENSIONS\GITHUB\GITHUB\GitHub.Exports.Reactive.dll	Yes	No	Skipped loading symbols.		189	2.05.4.3349	7/20/2018 4:12 PM	10910000-10928000	[6980] devenv.exe	[1] DefaultDomain	
Octokit.dll	Octokit.dll	C:\PROGRAM FILES (X86)\MICROSOFT VISUAL STUDIO\PREVIEW\PROFESSIONAL\COMMON7\IDE\EXTENSIONS\GITHUB\GITHUB\Octokit.dll	Yes	No	Skipped loading symbols.		190	0.29.0.0	7/20/2018 4:11 PM	120D0000-1218E000	[6980] devenv.exe	[1] DefaultDomain	
System.Reactive.Interfaces.dll	System.Reactive.Interfaces.dll	C:\PROGRAM FILES (X86)\MICROSOFT VISUAL STUDIO\PREVIEW\PROFESSIONAL\COMMON7\IDE\EXTENSIONS\GITHUB\GITHUB\System.Reactive.Interfaces.dll	Yes	No	Skipped loading symbols.		191	2.02.5.40722	5/6/2015 10:21 AM	10940000-10948000	[6980] devenv.exe	[1] DefaultDomain	
GitHub.Services.Vssdk.dll	GitHub.Services.Vssdk.dll	C:\PROGRAM FILES (X86)\MICROSOFT VISUAL STUDIO\PREVIEW\PROFESSIONAL\COMMON7\IDE\EXTENSIONS\GITHUB\GITHUB\GitHub.Services.Vssdk.dll	Yes	No	Skipped loading symbols.		192	2.05.4.3349	7/20/2018 4:12 PM	10950000-10958000	[6980] devenv.exe	[1] DefaultDomain	
Octokit.GraphQL.Core.dll	Octokit.GraphQL.Core.dll	c:\program files (x86)\microsoft visual studio\preview\professional\common7\ide\extensions\github\github\Octokit.GraphQL.Core.dll	Yes	No	Skipped loading symbols.		200	0.01.0.0	<Unknown>	12340000-12358000	[6980] devenv.exe	[1] DefaultDomain	
GitHub.VisualStudio.UI.dll	GitHub.VisualStudio.UI.dll	c:\program files (x86)\microsoft visual studio\preview\professional\common7\ide\extensions\github\github\GitHub.VisualStudio.UI.dll	Yes	No	Skipped loading symbols.		201	2.05.4.3349	7/20/2018 4:12 PM	123C0000-12414000	[6980] devenv.exe	[1] DefaultDomain	
System.Reactive.Core.dll	System.Reactive.Core.dll	C:\PROGRAM FILES (X86)\MICROSOFT VISUAL STUDIO\PREVIEW\PROFESSIONAL\COMMON7\IDE\EXTENSIONS\GITHUB\GITHUB\System.Reactive.Core.dll	Yes	No	Skipped loading symbols.		218	2.02.5.40722	5/6/2015 10:21 AM	16020000-1603E000	[6980] devenv.exe	[1] DefaultDomain	
GitHub.App.dll	GitHub.App.dll	C:\PROGRAM FILES (X86)\MICROSOFT VISUAL STUDIO\PREVIEW\PROFESSIONAL\COMMON7\IDE\EXTENSIONS\GITHUB\GITHUB\GitHub.App.dll	Yes	No	Skipped loading symbols.		219	2.05.4.3349	7/20/2018 4:12 PM	1BA60000-1BAEE000	[6980] devenv.exe	[1] DefaultDomain	
System.Reactive.Linq.dll	System.Reactive.Linq.dll	C:\PROGRAM FILES (X86)\MICROSOFT VISUAL STUDIO\PREVIEW\PROFESSIONAL\COMMON7\IDE\EXTENSIONS\GITHUB\GITHUB\System.Reactive.Linq.dll	Yes	No	Skipped loading symbols.		220	2.02.5.40722	5/6/2015 10:21 AM	1BBA0000-1BC4E000	[6980] devenv.exe	[1] DefaultDomain	
System.Reactive.PlatformServices.dll	System.Reactive.PlatformServices.dll	C:\PROGRAM FILES (X86)\MICROSOFT VISUAL STUDIO\PREVIEW\PROFESSIONAL\COMMON7\IDE\EXTENSIONS\GITHUB\GITHUB\System.Reactive.PlatformServices.dll	Yes	No	Skipped loading symbols.		221	2.02.5.40722	5/6/2015 10:21 AM	16590000-1659C000	[6980] devenv.exe	[1] DefaultDomain	
System.Reactive.Windows.Threading.dll	System.Reactive.Windows.Threading.dll	C:\PROGRAM FILES (X86)\MICROSOFT VISUAL STUDIO\PREVIEW\PROFESSIONAL\COMMON7\IDE\EXTENSIONS\GITHUB\GITHUB\System.Reactive.Windows.Threading.dll	Yes	No	Skipped loading symbols.		222	2.02.5.40722	5/6/2015 10:21 AM	165B0000-165BA000	[6980] devenv.exe	[1] DefaultDomain	
GitHub.UI.dll	GitHub.UI.dll	C:\PROGRAM FILES (X86)\MICROSOFT VISUAL STUDIO\PREVIEW\PROFESSIONAL\COMMON7\IDE\EXTENSIONS\GITHUB\GITHUB\GitHub.UI.dll	Yes	No	Skipped loading symbols.		223	2.05.4.3349	7/20/2018 4:12 PM	1BAF0000-1BB36000	[6980] devenv.exe	[1] DefaultDomain	
GitHub.CredentialManagement.dll	GitHub.CredentialManagement.dll	c:\program files (x86)\microsoft visual studio\preview\professional\common7\ide\extensions\github\github\GitHub.CredentialManagement.dll	Yes	No	Skipped loading symbols.		227	2.05.4.3349	7/20/2018 4:11 PM	1BC80000-1BC8A000	[6980] devenv.exe	[1] DefaultDomain	

[abhitalks]

@grokys here:

GitHub.VisualStudio.dll	GitHub.VisualStudio.dll	C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\Extensions\GitHub\GitHub\GitHub.VisualStudio.dll	Yes	No	Skipped loading symbols.		49	2.05.4.3349	21-Jul-2018 01:42	09950000-099A2000	[14920] devenv.exe	[1] DefaultDomain	
GitHub.Exports.dll	GitHub.Exports.dll	C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\Extensions\GitHub\GitHub\GitHub.Exports.dll	Yes	No	Skipped loading symbols.		67	2.05.4.3349	21-Jul-2018 01:42	02FB0000-02FD6000	[14920] devenv.exe	[1] DefaultDomain	
Serilog.dll	Serilog.dll	C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\Extensions\GitHub\GitHub\Serilog.dll	Yes	No	Skipped loading symbols.		69	2.05.0.0	<Unknown>	02FE0000-03002000	[14920] devenv.exe	[1] DefaultDomain	
GitHub.Api.dll	GitHub.Api.dll	C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\Extensions\GitHub\GitHub\GitHub.Api.dll	Yes	No	Skipped loading symbols.		74	2.05.4.3349	21-Jul-2018 01:42	03260000-03270000	[14920] devenv.exe	[1] DefaultDomain	
GitHub.Logging.dll	GitHub.Logging.dll	C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\Extensions\GitHub\GitHub\GitHub.Logging.dll	Yes	No	Skipped loading symbols.		77	2.05.4.3349	21-Jul-2018 01:41	032A0000-032A8000	[14920] devenv.exe	[1] DefaultDomain	
Rothko.dll	Rothko.dll	C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\Extensions\GitHub\GitHub\Rothko.dll	Yes	No	Skipped loading symbols.		79	0.00.3.0	11-Dec-2017 14:30	09520000-0954A000	[14920] devenv.exe	[1] DefaultDomain	
GitHub.TeamFoundation.15.dll	GitHub.TeamFoundation.15.dll	C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\Extensions\GitHub\GitHub\GitHub.TeamFoundation.15.dll	Yes	No	Skipped loading symbols.		85	2.05.4.3349	21-Jul-2018 01:42	09500000-09518000	[14920] devenv.exe	[1] DefaultDomain	
Serilog.Enrichers.Process.dll	Serilog.Enrichers.Process.dll	C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\Extensions\GitHub\GitHub\Serilog.Enrichers.Process.dll	Yes	No	Skipped loading symbols.		86	2.00.1.0	14-Feb-2017 16:42	09550000-09558000	[14920] devenv.exe	[1] DefaultDomain	
Serilog.Enrichers.Thread.dll	Serilog.Enrichers.Thread.dll	C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\Extensions\GitHub\GitHub\Serilog.Enrichers.Thread.dll	Yes	No	Skipped loading symbols.		88	3.00.0.0	14-Nov-2016 03:33	0C3F0000-0C3F8000	[14920] devenv.exe	[1] DefaultDomain	
Serilog.Sinks.File.dll	Serilog.Sinks.File.dll	C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\Extensions\GitHub\GitHub\Serilog.Sinks.File.dll	Yes	No	Skipped loading symbols.		89	3.02.0.0	03-Jan-2017 07:59	0DA00000-0DA0A000	[14920] devenv.exe	[1] DefaultDomain	
GitHub.Extensions.dll	GitHub.Extensions.dll	C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\Extensions\GitHub\GitHub\GitHub.Extensions.dll	Yes	No	Skipped loading symbols.		95	2.05.4.3349	21-Jul-2018 01:41	0D400000-0D40C000	[14920] devenv.exe	[1] DefaultDomain	
GitHub.UI.dll	GitHub.UI.dll	C:\PROGRAM FILES (X86)\MICROSOFT VISUAL STUDIO\2017\COMMUNITY\COMMON7\IDE\EXTENSIONS\GITHUB\GITHUB\GitHub.UI.dll	Yes	No	Skipped loading symbols.		110	2.05.4.3349	21-Jul-2018 01:42	0EF40000-0EF86000	[14920] devenv.exe	[1] DefaultDomain	
GitHub.VisualStudio.UI.dll	GitHub.VisualStudio.UI.dll	C:\PROGRAM FILES (X86)\MICROSOFT VISUAL STUDIO\2017\COMMUNITY\COMMON7\IDE\EXTENSIONS\GITHUB\GITHUB\GitHub.VisualStudio.UI.dll	Yes	No	Skipped loading symbols.		111	2.05.4.3349	21-Jul-2018 01:42	0EFF0000-0F044000	[14920] devenv.exe	[1] DefaultDomain	
GitHub.InlineReviews.dll	GitHub.InlineReviews.dll	C:\PROGRAM FILES (X86)\MICROSOFT VISUAL STUDIO\2017\COMMUNITY\COMMON7\IDE\EXTENSIONS\GITHUB\GITHUB\GitHub.InlineReviews.dll	Yes	No	Skipped loading symbols.		155	2.05.4.3349	21-Jul-2018 01:42	1AEE0000-1AF1C000	[14920] devenv.exe	[1] DefaultDomain	
LibGit2Sharp.dll	LibGit2Sharp.dll	C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\Extensions\GitHub\GitHub\LibGit2Sharp.dll	Yes	No	Skipped loading symbols.		201	0.23.1.0	09-Jan-2017 23:46	1E670000-1E6DE000	[14920] devenv.exe	[1] DefaultDomain	
GitHub.Services.Vssdk.dll	GitHub.Services.Vssdk.dll	C:\PROGRAM FILES (X86)\MICROSOFT VISUAL STUDIO\2017\COMMUNITY\COMMON7\IDE\EXTENSIONS\GITHUB\GITHUB\GitHub.Services.Vssdk.dll	Yes	No	Skipped loading symbols.		222	2.05.4.3349	21-Jul-2018 01:42	0D550000-0D558000	[14920] devenv.exe	[1] DefaultDomain	
GitHub.Exports.Reactive.dll	GitHub.Exports.Reactive.dll	C:\PROGRAM FILES (X86)\MICROSOFT VISUAL STUDIO\2017\COMMUNITY\COMMON7\IDE\EXTENSIONS\GITHUB\GITHUB\GitHub.Exports.Reactive.dll	Yes	No	Skipped loading symbols.		242	2.05.4.3349	21-Jul-2018 01:42	1E3A0000-1E3B8000	[14920] devenv.exe	[1] DefaultDomain	
GitHub.App.dll	GitHub.App.dll	C:\PROGRAM FILES (X86)\MICROSOFT VISUAL STUDIO\2017\COMMUNITY\COMMON7\IDE\EXTENSIONS\GITHUB\GITHUB\GitHub.App.dll	Yes	No	Skipped loading symbols.		243	2.05.4.3349	21-Jul-2018 01:42	21560000-215EE000	[14920] devenv.exe	[1] DefaultDomain	
ReactiveUI.dll	ReactiveUI.dll	C:\PROGRAM FILES (X86)\MICROSOFT VISUAL STUDIO\2017\COMMUNITY\COMMON7\IDE\EXTENSIONS\GITHUB\GITHUB\ReactiveUI.dll	Yes	No	Skipped loading symbols.		246	6.03.1.0	21-Jul-2018 01:41	20760000-207A2000	[14920] devenv.exe	[1] DefaultDomain	
System.Reactive.Interfaces.dll	System.Reactive.Interfaces.dll	C:\PROGRAM FILES (X86)\MICROSOFT VISUAL STUDIO\2017\COMMUNITY\COMMON7\IDE\EXTENSIONS\GITHUB\GITHUB\System.Reactive.Interfaces.dll	Yes	No	Skipped loading symbols.		247	2.02.5.40722	06-May-2015 19:51	20710000-20718000	[14920] devenv.exe	[1] DefaultDomain	
System.Reactive.Linq.dll	System.Reactive.Linq.dll	C:\PROGRAM FILES (X86)\MICROSOFT VISUAL STUDIO\2017\COMMUNITY\COMMON7\IDE\EXTENSIONS\GITHUB\GITHUB\System.Reactive.Linq.dll	Yes	No	Skipped loading symbols.		248	2.02.5.40722	06-May-2015 19:51	21340000-213EE000	[14920] devenv.exe	[1] DefaultDomain	
System.Reactive.Core.dll	System.Reactive.Core.dll	C:\PROGRAM FILES (X86)\MICROSOFT VISUAL STUDIO\2017\COMMUNITY\COMMON7\IDE\EXTENSIONS\GITHUB\GITHUB\System.Reactive.Core.dll	Yes	No	Skipped loading symbols.		249	2.02.5.40722	06-May-2015 19:51	207D0000-207EE000	[14920] devenv.exe	[1] DefaultDomain	
Octokit.dll	Octokit.dll	C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\Extensions\GitHub\GitHub\Octokit.dll	Yes	No	Skipped loading symbols.		250	0.29.0.0	21-Jul-2018 01:41	216E0000-2179E000	[14920] devenv.exe	[1] DefaultDomain	
Splat.dll	Splat.dll	C:\PROGRAM FILES (X86)\MICROSOFT VISUAL STUDIO\2017\COMMUNITY\COMMON7\IDE\EXTENSIONS\GITHUB\GITHUB\Splat.dll	Yes	No	Skipped loading symbols.		251	1.06.2.0	21-Jul-2018 01:41	20810000-20822000	[14920] devenv.exe	[1] DefaultDomain	
System.Reactive.PlatformServices.dll	System.Reactive.PlatformServices.dll	C:\PROGRAM FILES (X86)\MICROSOFT VISUAL STUDIO\2017\COMMUNITY\COMMON7\IDE\EXTENSIONS\GITHUB\GITHUB\System.Reactive.PlatformServices.dll	Yes	No	Skipped loading symbols.		252	2.02.5.40722	06-May-2015 19:51	207F0000-207FC000	[14920] devenv.exe	[1] DefaultDomain	
System.Reactive.Windows.Threading.dll	System.Reactive.Windows.Threading.dll	C:\PROGRAM FILES (X86)\MICROSOFT VISUAL STUDIO\2017\COMMUNITY\COMMON7\IDE\EXTENSIONS\GITHUB\GITHUB\System.Reactive.Windows.Threading.dll	Yes	No	Skipped loading symbols.		253	2.02.5.40722	06-May-2015 19:51	20800000-2080A000	[14920] devenv.exe	[1] DefaultDomain	
GitHub.CredentialManagement.dll	GitHub.CredentialManagement.dll	C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\Extensions\GitHub\GitHub\GitHub.CredentialManagement.dll	Yes	No	Skipped loading symbols.		254	2.05.4.3349	21-Jul-2018 01:41	209F0000-209FA000	[14920] devenv.exe	[1] DefaultDomain	
GitHub.UI.Reactive.dll	GitHub.UI.Reactive.dll	C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\Extensions\GitHub\GitHub\GitHub.UI.Reactive.dll	Yes	No	Skipped loading symbols.		291	2.05.4.3349	21-Jul-2018 01:42	0DE10000-0DE26000	[14920] devenv.exe	[1] DefaultDomain	
Octokit.GraphQL.Core.dll	Octokit.GraphQL.Core.dll	C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\Extensions\GitHub\GitHub\Octokit.GraphQL.Core.dll	Yes	No	Skipped loading symbols.		293	0.01.0.0	<Unknown>	0F170000-0F188000	[14920] devenv.exe	[1] DefaultDomain	
System.Windows.Interactivity.dll	System.Windows.Interactivity.dll	C:\PROGRAM FILES (X86)\MICROSOFT VISUAL STUDIO\2017\COMMUNITY\COMMON7\IDE\EXTENSIONS\GITHUB\GITHUB\System.Windows.Interactivity.dll	Yes	No	Skipped loading symbols.		295	3.00.40218.0	19-Feb-2013 04:46	0FC20000-0FC30000	[14920] devenv.exe	[1] DefaultDomain	
Akavache.dll	Akavache.dll	C:\PROGRAM FILES (X86)\MICROSOFT VISUAL STUDIO\2017\COMMUNITY\COMMON7\IDE\EXTENSIONS\GITHUB\GITHUB\Akavache.dll	Yes	No	Skipped loading symbols.		308	4.01.2.0	21-Jul-2018 01:42	13320000-13338000	[14920] devenv.exe	[1] DefaultDomain	

[grokys]

Thanks @vaindil @abhitalks! That's strange. The missing export that you're both seeing is declared in GitHub.VisualStudio.dll and that is loaded into devenv.exe with the correct version. So why is VS unable to find it?

[jcansdale]

@vaindil @ManlyBoy @abhitalks @bambam88 we're struggling to reproduce the issue but the problem is obviously quite widespread.

It looks like there might be something going wrong when Visual Studio tries to initialize the MEF cache. If you used the ClearMEFComponentCache extension to clear the cache, could you use the Show MEF Errors command (also on the Tools menu) to view the log.

If you could upload it here, that would be much appreciated. I'm hoping there will be a mention if GitHub somewhere in the log. If the log is empty, could you try running the Clear MEF Component Cache... command again.

If you didn't use the ClearMEFComponentCache extension, could you install it and use the Show MEF Errors command above. Here's the extension:
https://marketplace.visualstudio.com/items?itemName=MadsKristensen.ClearMEFComponentCache