Problem

When attempting to start SourceTree, the following dialog is displayed with the message "SourceTree has stopped working", and the application does not start: 

Diagnosis

Diagnostic Steps

• Open the Event Viewer in Windows right after the crash
• Go to Windows Logs >> Application
• There should be two Error entries.

• One of them has as Source: .NET Runtime

  Application: SourceTree.exe
  Framework Version: v4.0.30319
  Description: The process was terminated due to an unhandled exception.
  Exception Info: System.Configuration.ConfigurationErrorsException
  Stack:
     at System.Configuration.ConfigurationSchemaErrors.ThrowIfErrors(Boolean)
     at System.Configuration.BaseConfigurationRecord.ThrowIfParseErrors(System.Configuration.ConfigurationSchemaErrors)
     at System.Configuration.Configuration..ctor(System.String, System.Type, System.Object[])
     at System.Configuration.ClientConfigurationHost.OpenExeConfiguration(System.Configuration.ConfigurationFileMap, Boolean, System.Configuration.ConfigurationUserLevel, System.String)
     at System.Configuration.ConfigurationManager.OpenExeConfigurationImpl(System.Configuration.ConfigurationFileMap, Boolean, System.Configuration.ConfigurationUserLevel, System.String, Boolean)
     at SourceTree.App.SetStartupJIT()
     at SourceTree.App..ctor()
     at SourceTree.App.Main()

• The second one has as Source: Application Error

  Faulting application name: SourceTree.exe, version: 1.8.3.0, time stamp: 0x56f18db8
  Faulting module name: KERNELBASE.dll, version: 6.1.7600.16385, time stamp: 0x4a5bdfe0
  Exception code: 0xe0434352
  Fault offset: 0x000000000000aa7d
  Faulting process id: 0xb54
  Faulting application start time: 0x01d1d3a51746a7d1
  Faulting application path: C:\Program Files (x86)\Atlassian\SourceTree\SourceTree.exe
  Faulting module path: C:\Windows\system32\KERNELBASE.dll
  Report Id: 550f6aff-3f98-11e6-a681-0800279df20e

Cause

The most likely reason for this error is that the user.config file for SourceTree has been corrupted.

You can confirm this by locating the file in this location:

C:\Users\<User>\AppData\Local\Atlassian\SourceTree.exe_<random_string>\<version_number>

If this is the cause, when you open the file, it will be full of <NULL> values.

Resolution

If the user.config file is indeed corrupted, you may delete it.

It will be regenerated the next time you start SourceTree, and the application should start normally.