Steps prior to crash:

1. Updated SourceTree to new 1.6.14 version
2. File -> Clone/New -> Add Working Copy
   1. Wanted to upload a working copy into SourceTree I had cloned through Netbeans
3. Working copy was successfully load, but wasn't up to date with Remote (Stash) repo
   1. it seemed to be getting the changes from Stash when it crashed:

      2015-03-05T09:35:45: Fatal error: 
      System.NullReferenceException: Object reference not set to an instance of an object.
      
      2015-03-05T09:35:45: Stack trace: 
         at SourceTree.Model.FileStatusRecord.Equals(Object obj) in c:\projects\atlassian.com\dev\bitbucket.org\sourcetreewin\Model\FileStatusRecord.cs:line 180
         at System.Collections.Generic.ObjectEqualityComparer`1.Equals(T x, T y)
         at System.Collections.Generic.HashSet`1.AddIfNotPresent(T value)
         at SourceTree.Utils.ViewHelper.ExpandedFileRecords(IEnumerable`1 fileTree) in c:\projects\atlassian.com\dev\bitbucket.org\sourcetreewin\Utils\ViewHelper.cs:line 212
         at SourceTree.Utils.ViewHelper.ExpandedFileRecords(IEnumerable`1 fileTree) in c:\projects\atlassian.com\dev\bitbucket.org\sourcetreewin\Utils\ViewHelper.cs:line 213
         at SourceTree.Utils.ViewHelper.ExpandedFilePaths(IEnumerable`1 fileTree) in c:\projects\atlassian.com\dev\bitbucket.org\sourcetreewin\Utils\ViewHelper.cs:line 183
         at SourceTree.ViewModel.ChangeSets.CommitChangeSetViewModel.<RefreshForCommit>d__2b.MoveNext() in c:\projects\atlassian.com\dev\bitbucket.org\sourcetreewin\ViewModel\ChangeSets\CommitChangeSetViewModel.cs:line 346
      --- End of stack trace from previous location where exception was thrown ---
         at System.Runtime.CompilerServices.AsyncMethodBuilderCore.<ThrowAsync>b__0(Object state)
         at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
         at MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler)
      

I restarted SourceTree and noticed that master is 14 behind remote.