Sourcetree startup error 3.4.9

[ACL]

After upgrading to 3.4.9 multiple users are unable to launch Sourcetree
The splash screen pops up and disappears.

log file shows:

ERROR [2022-11-10 14:23:27,694] [1] [Sourcetree.Composition.VSMef.Net48.CompositionExceptionHelper] [Log] - CompositionException [Errors occurred during discovery.]
ERROR [2022-11-10 14:23:27,717] [1] [Sourcetree.Composition.VSMef.Net48.CompositionExceptionHelper] [Log] - Aggregate Exception:
System.AggregateException: One or more errors occurred. ---> Microsoft.VisualStudio.Composition.PartDiscoveryException: Failure while scanning type "SourceTree.ViewModel.RepositoryTabContainerViewModel". ---> System.TypeLoadException: Could not load type 'SourceTree.Api.Analytics.IAnalyticsService' from assembly 'SourceTree.Api.Analytics, Version=3.3.6.3829, Culture=neutral, PublicKeyToken=null'.
at System.Signature.GetSignature(Void* pCorSig, Int32 cCorSig, RuntimeFieldHandleInternal fieldHandle, IRuntimeMethodInfo methodHandle, RuntimeType declaringType)
at System.Signature..ctor(IRuntimeFieldInfo fieldHandle, RuntimeType declaringType)
at System.Reflection.RtFieldInfo.get_FieldType()
at Microsoft.VisualStudio.Composition.AttributedPartDiscoveryV1.AddImportsFromMembers(PropertyInfo[] declaredProperties, FieldInfo[] declaredFields, TypeRef partTypeRef, IList`1 imports)
at Microsoft.VisualStudio.Composition.AttributedPartDiscoveryV1.CreatePart(Type partType, Boolean typeExplicitlyRequested)
at Microsoft.VisualStudio.Composition.PartDiscovery.CombinedPartDiscovery.CreatePart(Type partType, Boolean typeExplicitlyRequested)
at Microsoft.VisualStudio.Composition.PartDiscovery.<>c__DisplayClass27_0.<CreateDiscoveryBlockChain>b__0(Type type)
--- End of inner exception stack trace ---
--- End of inner exception stack trace ---
---> (Inner Exception #0) Microsoft.VisualStudio.Composition.PartDiscoveryException: Failure while scanning type "SourceTree.ViewModel.RepositoryTabContainerViewModel". ---> System.TypeLoadException: Could not load type 'SourceTree.Api.Analytics.IAnalyticsService' from assembly 'SourceTree.Api.Analytics, Version=3.3.6.3829, Culture=neutral, PublicKeyToken=null'.
at System.Signature.GetSignature(Void* pCorSig, Int32 cCorSig, RuntimeFieldHandleInternal fieldHandle, IRuntimeMethodInfo methodHandle, RuntimeType declaringType)
at System.Signature..ctor(IRuntimeFieldInfo fieldHandle, RuntimeType declaringType)
at System.Reflection.RtFieldInfo.get_FieldType()
at Microsoft.VisualStudio.Composition.AttributedPartDiscoveryV1.AddImportsFromMembers(PropertyInfo[] declaredProperties, FieldInfo[] declaredFields, TypeRef partTypeRef, IList`1 imports)
at Microsoft.VisualStudio.Composition.AttributedPartDiscoveryV1.CreatePart(Type partType, Boolean typeExplicitlyRequested)
at Microsoft.VisualStudio.Composition.PartDiscovery.CombinedPartDiscovery.CreatePart(Type partType, Boolean typeExplicitlyRequested)
at Microsoft.VisualStudio.Composition.PartDiscovery.<>c__DisplayClass27_0.<CreateDiscoveryBlockChain>b__0(Type type)
--- End of inner exception stack trace ---<---

ERROR [2022-11-10 14:23:27,724] [1] [Sourcetree.Composition.VSMef.Net48.CompositionExceptionHelper] [Log] - PartDiscoveryException:
Microsoft.VisualStudio.Composition.PartDiscoveryException: Failure while scanning type "SourceTree.ViewModel.RepositoryTabContainerViewModel". ---> System.TypeLoadException: Could not load type 'SourceTree.Api.Analytics.IAnalyticsService' from assembly 'SourceTree.Api.Analytics, Version=3.3.6.3829, Culture=neutral, PublicKeyToken=null'.
at System.Signature.GetSignature(Void* pCorSig, Int32 cCorSig, RuntimeFieldHandleInternal fieldHandle, IRuntimeMethodInfo methodHandle, RuntimeType declaringType)
at System.Signature..ctor(IRuntimeFieldInfo fieldHandle, RuntimeType declaringType)
at System.Reflection.RtFieldInfo.get_FieldType()
at Microsoft.VisualStudio.Composition.AttributedPartDiscoveryV1.AddImportsFromMembers(PropertyInfo[] declaredProperties, FieldInfo[] declaredFields, TypeRef partTypeRef, IList`1 imports)
at Microsoft.VisualStudio.Composition.AttributedPartDiscoveryV1.CreatePart(Type partType, Boolean typeExplicitlyRequested)
at Microsoft.VisualStudio.Composition.PartDiscovery.CombinedPartDiscovery.CreatePart(Type partType, Boolean typeExplicitlyRequested)
at Microsoft.VisualStudio.Composition.PartDiscovery.<>c__DisplayClass27_0.<CreateDiscoveryBlockChain>b__0(Type type)
--- End of inner exception stack trace ---

Has anyone seen this before or have any ideas please? thanks!

[ACL · Accepted solution]

Managed to fix - the issue was being caused by upgrading from a previous version to the new one.

So manually deleted the sourcetree install folder and then installing the new one works.