SourceTree is not starting up anymore 17.05.2024)
Asked by C:

I have this error in the log:  
ERROR \[2024-05-17 13:35:51,662\] \[1\] \[Sourcetree.Composition.VSMef.Net48.VSMefCompositionManager\] \[Log\] - Unable to load MEF components  
System.ArgumentException: The number of generic arguments provided doesn't equal the arity of the generic type definition.  
Parameter name: instantiation  
at System.RuntimeType.MakeGenericType(Type\[\] instantiation)  
at Microsoft.VisualStudio.Composition.Reflection.TypeRef.get_ResolvedType()  
at Microsoft.VisualStudio.Composition.RuntimeComposition.RuntimeImport.get_ImportingSiteTypeWithoutCollection()  
at Microsoft.VisualStudio.Composition.RuntimeComposition.RuntimeImport.get_IsLazy()  
at Microsoft.VisualStudio.Composition.RuntimeComposition.RuntimeImport.get_LazyFactory()  
at Microsoft.VisualStudio.Composition.RuntimeExportProviderFactory.RuntimeExportProvider.GetValueForImportSite(RuntimePartLifecycleTracker importingPartTracker, RuntimeImport import)  
at Microsoft.VisualStudio.Composition.RuntimeExportProviderFactory.RuntimeExportProvider.RuntimePartLifecycleTracker.SatisfyImports()  
at Microsoft.VisualStudio.Composition.ExportProvider.PartLifecycleTracker.SatisfyImmediateImports()  
at Microsoft.VisualStudio.Composition.ExportProvider.PartLifecycleTracker.MoveNext(PartLifecycleState nextState)  
at Microsoft.VisualStudio.Composition.ExportProvider.PartLifecycleTracker.MoveToState(PartLifecycleState requiredState)  
at Microsoft.VisualStudio.Composition.ExportProvider.PartLifecycleTracker.GetValueReadyToExpose()  
at Microsoft.VisualStudio.Composition.RuntimeExportProviderFactory.RuntimeExportProvider.\<\>c__DisplayClass15_0.\<GetExportedValueHelper\>b__0()  
at Microsoft.VisualStudio.Composition.RuntimeExportProviderFactory.RuntimeExportProvider.GetValueForImportElement(RuntimePartLifecycleTracker importingPartTracker, RuntimeImport import, RuntimeExport export, Func\`3 lazyFactory)  
at Microsoft.VisualStudio.Composition.RuntimeExportProviderFactory.RuntimeExportProvider.GetValueForImportSite(RuntimePartLifecycleTracker importingPartTracker, RuntimeImport import)  
at Microsoft.VisualStudio.Composition.RuntimeExportProviderFactory.RuntimeExportProvider.RuntimePartLifecycleTracker.\<CreateValue\>b__10_0(RuntimeImport import)  
at System.Linq.Enumerable.WhereSelectArrayIterator\`2.MoveNext()  
at System.Linq.Buffer\`1..ctor(IEnumerable\`1 source)  
at System.Linq.Enumerable.ToArray\[TSource\](IEnumerable\`1 source)  
at Microsoft.VisualStudio.Composition.RuntimeExportProviderFactory.RuntimeExportProvider.RuntimePartLifecycleTracker.CreateValue()  
at Microsoft.VisualStudio.Composition.ExportProvider.PartLifecycleTracker.Create()  
at Microsoft.VisualStudio.Composition.ExportProvider.PartLifecycleTracker.MoveNext(PartLifecycleState nextState)  
at Microsoft.VisualStudio.Composition.ExportProvider.PartLifecycleTracker.MoveToState(PartLifecycleState requiredState)  
at Microsoft.VisualStudio.Composition.ExportProvider.PartLifecycleTracker.GetValueReadyToExpose()  
at Microsoft.VisualStudio.Composition.RuntimeExportProviderFactory.RuntimeExportProvider.\<\>c__DisplayClass15_0.\<GetExportedValueHelper\>b__0()  
at Microsoft.VisualStudio.Composition.RuntimeExportProviderFactory.RuntimeExportProvider.GetValueForImportElement(RuntimePartLifecycleTracker importingPartTracker, RuntimeImport import, RuntimeExport export, Func\`3 lazyFactory)  
at Microsoft.VisualStudio.Composition.RuntimeExportProviderFactory.RuntimeExportProvider.GetValueForImportSite(RuntimePartLifecycleTracker importingPartTracker, RuntimeImport import)  
at Microsoft.VisualStudio.Composition.RuntimeExportProviderFactory.RuntimeExportProvider.RuntimePartLifecycleTracker.\<CreateValue\>b__10_0(RuntimeImport import)  
at System.Linq.Enumerable.WhereSelectArrayIterator\`2.MoveNext()  
at System.Linq.Buffer\`1..ctor(IEnumerable\`1 source)  
at System.Linq.Enumerable.ToArray\[TSource\](IEnumerable\`1 source)  
at Microsoft.VisualStudio.Composition.RuntimeExportProviderFactory.RuntimeExportProvider.RuntimePartLifecycleTracker.CreateValue()  
at Microsoft.VisualStudio.Composition.ExportProvider.PartLifecycleTracker.Create()  
at Microsoft.VisualStudio.Composition.ExportProvider.PartLifecycleTracker.MoveNext(PartLifecycleState nextState)  
at Microsoft.VisualStudio.Composition.ExportProvider.PartLifecycleTracker.MoveToState(PartLifecycleState requiredState)  
at Microsoft.VisualStudio.Composition.ExportProvider.PartLifecycleTracker.GetValueReadyToExpose()  
at System.Lazy\`1.CreateValue()  
at System.Lazy\`1.LazyInitValue()  
at Microsoft.VisualStudio.Composition.NetFxAdapters.MefV1ExportProvider.\<\>c__DisplayClass12_0.\<UnwrapExport\>b__1()  
at System.ComponentModel.Composition.Primitives.Export.get_Value()  
at System.ComponentModel.Composition.ReflectionModel.ImportingItem.Cast(Type type, Export export)  
at System.ComponentModel.Composition.ReflectionModel.ReflectionComposablePart.SetImport(ImportingItem item, Export\[\] exports)  
at System.ComponentModel.Composition.Hosting.ImportEngine.PartManager.TrySetImport(ImportDefinition import, Export\[\] exports)  
at System.ComponentModel.Composition.Hosting.ImportEngine.TrySatisfyImportSubset(PartManager partManager, IEnumerable\`1 imports, AtomicComposition atomicComposition)  
at System.ComponentModel.Composition.Hosting.ImportEngine.TrySatisfyImportsStateMachine(PartManager partManager, ComposablePart part)  
at System.ComponentModel.Composition.Hosting.ImportEngine.TrySatisfyImports(PartManager partManager, ComposablePart part, Boolean shouldTrackImports)  
at System.ComponentModel.Composition.Hosting.ImportEngine.SatisfyImportsOnce(ComposablePart part)  
at System.ComponentModel.Composition.Hosting.CompositionContainer.SatisfyImportsOnce(ComposablePart part)  
at System.ComponentModel.Composition.AttributedModelServices.SatisfyImportsOnce(ICompositionService compositionService, Object attributedPart)  
at Sourcetree.Composition.VSMef.Net48.VSMefCompositionManager.\<Compose\>d__5.MoveNext()  


Answers:
author: C
body: Found this <https://community.atlassian.com/t5/Sourcetree-questions/SourceTree-won-t-start-Unable-to-load-MEF-components/qaq-p/2388773>