Not able to start the sourcetree after install on windows 10

[Raj Ad]

I am not able to start the source tree.

Afer install, i was able to start one time.

I have installed Git later, now i am not able to start the sourcetree.

getting below error in sourcetree.log:

Also creating a newfile with below content

2020-03-02T10:14:23: CompositionException [Errors exist in the composition.]

ERROR [2020-03-02 10:12:47,370] [1] [Sourcetree.Composition.VSMef.Net471.CompositionExceptionHelper] [Log] - SourceTree.Host.Bitbucket.BitbucketCredentialsAdapter.ctor(remoteHostAuthenticationManager): expected exactly 1 export of SourceTree.Accounts.IRemoteHostAuthenticationManager but found 0.
ERROR [2020-03-02 10:12:47,370] [1] [Sourcetree.Composition.VSMef.Net471.CompositionExceptionHelper] [Log] - SourceTree.Host.Bitbucket.BitbucketHost.ctor(credentialsAdapter): expected exactly 1 export of SourceTree.Accounts.ICredentialsAdapter`1[System.Tuple`2[System.String,System.String]] but found 0.
ERROR [2020-03-02 10:14:23,529] [1] [Sourcetree.Composition.VSMef.Net471.CompositionExceptionHelper] [Log] - CompositionException [Errors exist in the composition.]
ERROR [2020-03-02 10:14:23,561] [1] [Sourcetree.Composition.VSMef.Net471.CompositionExceptionHelper] [Log] - SourceTree.Api.Account.OAuth.TwoZero.OAuthTwoZeroBearerAuthenticationManager.ctor(oauthTwoZeroInteractionsManager): expected exactly 1 export of SourceTree.Accounts.IRemoteHostAuthenticationInteractionsManager`1[SourceTree.Api.Account.OAuth.TwoZero.IOAuthTwoZeroOAuthConfiguration] but found 2.
SourceTree.Api.Account.OAuth.TwoZero.OAuthTwoZeroAuthenticationInteractionsManager
SourceTree.Account.OAuth.TwoZero.UI.Wpf.OAuthTwoZeroAuthenticationInteractionsManager
ERROR [2020-03-02 10:14:23,561] [1] [Sourcetree.Composition.VSMef.Net471.CompositionExceptionHelper] [Log] - SourceTree.Host.Bitbucket.BitbucketCredentialsAdapter.ctor(remoteHostAuthenticationManager): expected exactly 1 export of SourceTree.Accounts.IRemoteHostAuthenticationManager but found 0.
ERROR [2020-03-02 10:14:23,576] [1] [Sourcetree.Composition.VSMef.Net471.CompositionExceptionHelper] [Log] - SourceTree.Host.Bitbucket.BitbucketHost.ctor(credentialsAdapter): expected exactly 1 export of SourceTree.Accounts.ICredentialsAdapter`1[System.Tuple`2[System.String,System.String]] but found 0.

[SteveKovacs]

Ran into the same issue and the main clue was: 

expected exactly 1 export of SourceTree.Accounts.IRemoteHostAuthenticationInteractionsManager`1[SourceTree.Api.Account.OAuth.TwoZero.IOAuthTwoZeroOAuthConfiguration] but found 2.

After uninstalling SourceTree there was still some leftover cruft  in the C:\Program Files (x86)\Atlassian\Sourcetree path:

Deleting the C:\Program Files (x86)\Atlassian\Sourcetree folder and then reinstalling SourceTree resolved the issue for me.