I have last used Sourcetree on last Wed, 14Jun2023. Then since 19Jun. it has stopped launching with the following error found in sourcetree.log:
ERROR [2023-06-20 11:31:47,083] [1] [Sourcetree.Composition.VSMef.Net471.VSMefCompositionManager] [Log] - Unable to load MEF components
System.InvalidOperationException: Sequence contains no elements
at System.Linq.Enumerable.First[TSource](IEnumerable`1 source)
at Microsoft.VisualStudio.Composition.PartDiscovery.GetElementTypeFromMany(Type type)
at Microsoft.VisualStudio.Composition.RuntimeComposition.RuntimeImport.get_ImportingSiteTypeWithoutCollection