ERROR [2017-05-15 17:13:20,983] [1] [SourceTree.AppRoot] [InitializeMef] - CompositionException [The composition remains unchanged. The changes were rejected because of the following error(s): The composition produced multiple composition errors, with 21 root causes. The root causes are provided below. Review the CompositionException.Errors property for more detailed information.

1) No exports were found that match the constraint:
    ContractName    SourceTree.ViewModel.Repositories.IRepositoryTabContainerViewModel
    RequiredTypeIdentity    SourceTree.ViewModel.Repositories.IRepositoryTabContainerViewModel

Resulting in: Cannot set import 'SourceTree.AppRoot.RepositoryTabContainerViewModel (ContractName="SourceTree.ViewModel.Repositories.IRepositoryTabContainerViewModel")' on part 'SourceTree.AppRoot'.
Element: SourceTree.AppRoot.RepositoryTabContainerViewModel (ContractName="SourceTree.ViewModel.Repositories.IRepositoryTabContainerViewModel") -->  SourceTree.AppRoot

2) No exports were found that match the constraint:
    ContractName    SourceTree.Bookmarks.IBookmarkManager
    RequiredTypeIdentity    SourceTree.Bookmarks.IBookmarkManager

Resulting in: Cannot set import 'SourceTree.AppRoot.BookmarkManager (ContractName="SourceTree.Bookmarks.IBookmarkManager")' on part 'SourceTree.AppRoot'.
Element: SourceTree.AppRoot.BookmarkManager (ContractName="SourceTree.Bookmarks.IBookmarkManager") -->  SourceTree.AppRoot

3) No exports were found that match the constraint:
    ContractName    SourceTree.Repositories.IRepositoryMonitorManager
    RequiredTypeIdentity    SourceTree.Repositories.IRepositoryMonitorManager

Resulting in: Cannot set import 'SourceTree.AppRoot.RepositoryMonitorManager (ContractName="SourceTree.Repositories.IRepositoryMonitorManager")' on part 'SourceTree.AppRoot'.
Element: SourceTree.AppRoot.RepositoryMonitorManager (ContractName="SourceTree.Repositories.IRepositoryMonitorManager") -->  SourceTree.AppRoot

4) No exports were found that match the constraint:
    ContractName    SourceTree.Scheduler.ISchedulerManager
    RequiredTypeIdentity    SourceTree.Scheduler.ISchedulerManager

Resulting in: Cannot set import 'SourceTree.AppRoot.SchedulerManager (ContractName="SourceTree.Scheduler.ISchedulerManager")' on part 'SourceTree.AppRoot'.
Element: SourceTree.AppRoot.SchedulerManager (ContractName="SourceTree.Scheduler.ISchedulerManager") -->  SourceTree.AppRoot

5) No exports were found that match the constraint:
    ContractName    SourceTree.Diagnostics.IFailureHandler
    RequiredTypeIdentity    SourceTree.Diagnostics.IFailureHandler

Resulting in: Cannot set import 'SourceTree.AppRoot.FailureHandler (ContractName="SourceTree.Diagnostics.IFailureHandler")' on part 'SourceTree.AppRoot'.
Element: SourceTree.AppRoot.FailureHandler (ContractName="SourceTree.Diagnostics.IFailureHandler") -->  SourceTree.AppRoot

6) No exports were found that match the constraint:
    ContractName    SourceTree.Web.IWebManager
    RequiredTypeIdentity    SourceTree.Web.IWebManager

Resulting in: Cannot set import 'SourceTree.AppRoot.WebManager (ContractName="SourceTree.Web.IWebManager")' on part 'SourceTree.AppRoot'.
Element: SourceTree.AppRoot.WebManager (ContractName="SourceTree.Web.IWebManager") -->  SourceTree.AppRoot

7) No exports were found that match the constraint:
    ContractName    SourceTree.Security.IInteractionsManager
    RequiredTypeIdentity    SourceTree.Security.IInteractionsManager

Resulting in: Cannot set import 'SourceTree.AppRoot.InteractionsManager (ContractName="SourceTree.Security.IInteractionsManager")' on part 'SourceTree.AppRoot'.
Element: SourceTree.AppRoot.InteractionsManager (ContractName="SourceTree.Security.IInteractionsManager") -->  SourceTree.AppRoot

8) No exports were found that match the constraint:
    ContractName    SourceTree.Dvcss.IDvcsManager
    RequiredTypeIdentity    SourceTree.Dvcss.IDvcsManager

Resulting in: Cannot set import 'SourceTree.AppRoot.DvcsManager (ContractName="SourceTree.Dvcss.IDvcsManager")' on part 'SourceTree.AppRoot'.
Element: SourceTree.AppRoot.DvcsManager (ContractName="SourceTree.Dvcss.IDvcsManager") -->  SourceTree.AppRoot

9) No exports were found that match the constraint:
    ContractName    SourceTree.CustomActions.ICustomActionsManager
    RequiredTypeIdentity    SourceTree.CustomActions.ICustomActionsManager

Resulting in: Cannot set import 'SourceTree.AppRoot.CustomActionsManager (ContractName="SourceTree.CustomActions.ICustomActionsManager")' on part 'SourceTree.AppRoot'.
Element: SourceTree.AppRoot.CustomActionsManager (ContractName="SourceTree.CustomActions.ICustomActionsManager") -->  SourceTree.AppRoot

10) No exports were found that match the constraint:
    ContractName    SourceTree.Scheduler.IDispatcher
    RequiredTypeIdentity    SourceTree.Scheduler.IDispatcher

Resulting in: Cannot set import 'SourceTree.AppRoot.Dispatcher (ContractName="SourceTree.Scheduler.IDispatcher")' on part 'SourceTree.AppRoot'.
Element: SourceTree.AppRoot.Dispatcher (ContractName="SourceTree.Scheduler.IDispatcher") -->  SourceTree.AppRoot

11) No exports were found that match the constraint:
    ContractName    SourceTree.Accounts.IAccountManager
    RequiredTypeIdentity    SourceTree.Accounts.IAccountManager

Resulting in: Cannot set import 'SourceTree.AppRoot.AccountManager (ContractName="SourceTree.Accounts.IAccountManager")' on part 'SourceTree.AppRoot'.
Element: SourceTree.AppRoot.AccountManager (ContractName="SourceTree.Accounts.IAccountManager") -->  SourceTree.AppRoot

12) No exports were found that match the constraint:
    ContractName    SourceTree.Repositories.IRepositoryManager
    RequiredTypeIdentity    SourceTree.Repositories.IRepositoryManager

Resulting in: Cannot set import 'SourceTree.AppRoot.RepositoryManager (ContractName="SourceTree.Repositories.IRepositoryManager")' on part 'SourceTree.AppRoot'.
Element: SourceTree.AppRoot.RepositoryManager (ContractName="SourceTree.Repositories.IRepositoryManager") -->  SourceTree.AppRoot

13) No exports were found that match the constraint:
    ContractName    SourceTree.View.ChangeSets.IChangeSetViewManager
    RequiredTypeIdentity    SourceTree.View.ChangeSets.IChangeSetViewManager

Resulting in: Cannot set import 'SourceTree.AppRoot.ChangeSetViewManager (ContractName="SourceTree.View.ChangeSets.IChangeSetViewManager")' on part 'SourceTree.AppRoot'.
Element: SourceTree.AppRoot.ChangeSetViewManager (ContractName="SourceTree.View.ChangeSets.IChangeSetViewManager") -->  SourceTree.AppRoot

14) No exports were found that match the constraint:
    ContractName    SourceTree.Applications.IApplicationManager
    RequiredTypeIdentity    SourceTree.Applications.IApplicationManager

Resulting in: Cannot set import 'SourceTree.AppRoot.ApplicationManager (ContractName="SourceTree.Applications.IApplicationManager")' on part 'SourceTree.AppRoot'.
Element: SourceTree.AppRoot.ApplicationManager (ContractName="SourceTree.Applications.IApplicationManager") -->  SourceTree.AppRoot

15) No exports were found that match the constraint:
    ContractName    SourceTree.Security.ISshKeyManager
    RequiredTypeIdentity    SourceTree.Security.ISshKeyManager

Resulting in: Cannot set import 'SourceTree.AppRoot.SshKeyManager (ContractName="SourceTree.Security.ISshKeyManager")' on part 'SourceTree.AppRoot'.
Element: SourceTree.AppRoot.SshKeyManager (ContractName="SourceTree.Security.ISshKeyManager") -->  SourceTree.AppRoot

16) No exports were found that match the constraint:
    ContractName    SourceTree.Utils.IRepoProcessFactory
    RequiredTypeIdentity    SourceTree.Utils.IRepoProcessFactory

Resulting in: Cannot set import 'SourceTree.AppRoot.RepoProcessFactory (ContractName="SourceTree.Utils.IRepoProcessFactory")' on part 'SourceTree.AppRoot'.
Element: SourceTree.AppRoot.RepoProcessFactory (ContractName="SourceTree.Utils.IRepoProcessFactory") -->  SourceTree.AppRoot

17) No exports were found that match the constraint:
    ContractName    SourceTree.Download.IDownloadManager
    RequiredTypeIdentity    SourceTree.Download.IDownloadManager

Resulting in: Cannot set import 'SourceTree.AppRoot.DownloadManager (ContractName="SourceTree.Download.IDownloadManager")' on part 'SourceTree.AppRoot'.
Element: SourceTree.AppRoot.DownloadManager (ContractName="SourceTree.Download.IDownloadManager") -->  SourceTree.AppRoot

18) No exports were found that match the constraint:
    ContractName    SourceTree.Api.Host.View.Hosted.IHostUiManager
    RequiredTypeIdentity    SourceTree.Api.Host.View.Hosted.IHostUiManager

Resulting in: Cannot set import 'SourceTree.AppRoot.HostUiManager (ContractName="SourceTree.Api.Host.View.Hosted.IHostUiManager")' on part 'SourceTree.AppRoot'.
Element: SourceTree.AppRoot.HostUiManager (ContractName="SourceTree.Api.Host.View.Hosted.IHostUiManager") -->  SourceTree.AppRoot

19) No exports were found that match the constraint:
    ContractName    SourceTree.Accounts.IAuthenticationUIManager
    RequiredTypeIdentity    SourceTree.Accounts.IAuthenticationUIManager

Resulting in: Cannot set import 'SourceTree.AppRoot.AuthenticationUiManager (ContractName="SourceTree.Accounts.IAuthenticationUIManager")' on part 'SourceTree.AppRoot'.
Element: SourceTree.AppRoot.AuthenticationUiManager (ContractName="SourceTree.Accounts.IAuthenticationUIManager") -->  SourceTree.AppRoot

20) No exports were found that match the constraint:
    ContractName    SourceTree.Onboarding.IOnboardingManager
    RequiredTypeIdentity    SourceTree.Onboarding.IOnboardingManager

Resulting in: Cannot set import 'SourceTree.AppRoot.OnboardingManager (ContractName="SourceTree.Onboarding.IOnboardingManager")' on part 'SourceTree.AppRoot'.
Element: SourceTree.AppRoot.OnboardingManager (ContractName="SourceTree.Onboarding.IOnboardingManager") -->  SourceTree.AppRoot

21) No exports were found that match the constraint:
    ContractName    System.Preferences.IPreferencesManager
    RequiredTypeIdentity    System.Preferences.IPreferencesManager

Resulting in: Cannot set import 'SourceTree.AppRoot.PreferencesManager (ContractName="System.Preferences.IPreferencesManager")' on part 'SourceTree.AppRoot'.
Element: SourceTree.AppRoot.PreferencesManager (ContractName="System.Preferences.IPreferencesManager") -->  SourceTree.AppRoot
]
ERROR [2017-05-15 17:13:23,435] [1] [SourceTree.App] [OnStartup] - Failed to start
System.ArgumentNullException: Value cannot be null.
Parameter name: source
   at System.Linq.OrderedEnumerable`2..ctor(IEnumerable`1 source, Func`2 keySelector, IComparer`1 comparer, Boolean descending)
   at SourceTree.AppRoot.InitializeCrashAnaylyticsServices()
   at SourceTree.AppRoot.OnStartup(StartupEventArgs e)
   at SourceTree.App.OnStartup(StartupEventArgs e)
2017-05-15T17:13:40: Unable to extract http://downloads.atlassian.com/software/sourcetree/windows/PortableHg_3.2.3.7z: System.Net.WebException: The remote server returned an error: (407) Proxy Authentication Required.