SourceTree won't start - Unable to load MEF components

[Sven Schuchmann]

Hi,

I am using SourceTree Enterprise 3.4.13.0 on Windows 10.
After a Windows Update Today it does not start anymore.
Only see splash screen then it closes.
Tried uninstalling Reinstalling, nothing helped.

In the SourceTree.log I see this error:

ERROR [2023-06-14 09:23:59,047] [1] [Sourcetree.Composition.VSMef.Net48.VSMefCompositionManager] [Log] - Unable to load MEF components
System.InvalidOperationException: Die Sequenz enthält keine Elemente.
bei System.Linq.Enumerable.First[TSource](IEnumerable`1 source)
bei Microsoft.VisualStudio.Composition.PartDiscovery.GetElementTypeFromMany(Type type)
bei Microsoft.VisualStudio.Composition.RuntimeComposition.RuntimeImport.get_ImportingSiteTypeWithoutCollection()
bei Microsoft.VisualStudio.Composition.RuntimeComposition.RuntimeImport.get_IsLazy()
bei Microsoft.VisualStudio.Composition.RuntimeComposition.RuntimeImport.get_LazyFactory()
bei Microsoft.VisualStudio.Composition.RuntimeExportProviderFactory.RuntimeExportProvider.GetValueForImportSite(RuntimePartLifecycleTracker importingPartTracker, RuntimeImport import)
bei Microsoft.VisualStudio.Composition.RuntimeExportProviderFactory.RuntimeExportProvider.RuntimePartLifecycleTracker.SatisfyImports()
...

Can anyone help?

[Sven Schuchmann · Accepted solution]

Deleting

%LOCALAPPDATA%\Atlassian\SourceTree.exe_<UID>\3.4.13.0\Assemblies.cache
%LOCALAPPDATA%\Atlassian\SourceTree.exe_<UID>\3.4.13.0\Composition.cache

helped!

[Richard Jackson]

This worked for me too

[Tomas Franco]

Thank you so much glad someone was able to solve this.

[Kevin Henderson]

Same issue for me and this worked. Thanks!

[Oddvar Gjerde]

Very helpful for me too

[Heidi Bickner]

Very helpful. Thanks for posting!

[Jachin Collins]

FYI - On my machine, the files were located under the Atlassian folder:

%LOCALAPPDATA%\Atlassian\SourceTree.exe_<UID>\<Version>\

[Heidi Bickner]

@Jachin CollinsSame

[Sven Schuchmann]

@Jachin Collins Correct, I fixed that in my answer.

[COMM_IT]

Worke for me as well, thanks!

[양기탁]

고맙습니다. 덕분에 해결 했습니다!

[FrogsInSpace]

Seems that this issue reappears and the above fix has to be applied repeatetly
So i downgraded to 3.4.12 and the issue is gone

Seems to be some deeper issue with the 3.4.13 version

[Michael Eacott]

Thanks for posting. This worked for me.

[Chris Plenter]

Works! Thanks for the post!

[Jordan Brobyn]

Worked for me

[Liam Murphy]

Worked for me after this weeks regular windows update that I declined but somehow it was applied regardless. For what its worth these are the folders in which I needed to delete those files:

C:\Users\**me**\AppData\Local\Atlassian\SourceTree.exe_Url_re5thcoffnnkdlp540ilqzrn33oj41rm\3.4.3.0

C:\Users\**me**\AppData\Local\Atlassian\SourceTree.exe_Url_n3rdypildipi022uybkie3xafvtaqehx\3.4.8.0

[Andrew Neil]

Worked here too! Awesome!

[Patrik Foldes]

Thanks, helped me too

[arizagaander]

Same problem. Solution works like a charm

Thanks!

[Samantha Roderigues]

worked for me too thanks!

[Ravichandran M Kaushika]

Worked for me - thanks a bunch.

[Teddy Saputra]

Worked perfectly thanks!

[Joel Blake]

Worked for me!

[oksana_vovere]

Thanks! 

[Prashanth Bala]

Thanks, that worked for me!

[Ivan Lopez]

It works for me too. Thanks a lot!!!!

[Eric Yu]

It works for me too, thanks!

[Paresh Awashank]

Worked for me.. thanks!!!

[Darren Capner]

This worked for me. Thanks!

[Qreesna]

Thanks. It works!

[Martí Pàmies Solà]

Thks so much. it works

[FerneyMartinez]

Thanks so much. It worked like a charm!!

[jszbps]

This worked!

"Unable to load MEF components" is not a bug, it's a feature! This happens so frequently it's disturbing why developers do not fix this or auto-remediate for this issue. Incredibly frustrating when this happens.

EDIT: Got tired of this issue happening so often, even on latest version at time of writing, so I stopped using Atlassian SourceTree altogether and started using something else.

[gmayer]

Thank you so much!!

[Charles Benson]

Thank you so very much!  A big relief. Thank you.

[charlesstanding]

This worked beautifully (on v 3.4.11). Thank you so much!

[Mukesh Kumar]

We have fixed this issue in Sourcetree 3.4.14 and is available for upgrade.

[Harry Playfair]

Exact same issue here, deleting the single file solved it:

Composition.cache

However, the problem has recurred twice - will we see a fix soon?

[Caleb Widmer]

came here same reason,
thanks for the work arounds.
Uninstall/reinstall seems to work at least from SourceTree-3.4.8 to 3.4.13

[Richard Jackson]

I have the same issue

[Sven Schuchmann]

Can you check my answer below helps?

[Richard Jackson]

yes, its fixed

[zsw]

Thank for you help♥

[Eric Bongaerts]

Works for me as well. Thnx!

[Radek Havelka]

had the same issue, deleting the files helped, thanks !

[Ivan Lopez]

It works for me too. Thanks a lot!!

[Sean Lively]

My entire team got bit by this bug after recent windows updates.

[StuartWhiting]

same thing happened here. glad to find this post quickly.