Click on a checkin and got the following error log:

2015-06-08T07:48:38: Fatal error:
System.NullReferenceException: Object reference not set to an instance of an object.

2015-06-08T07:48:38: 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.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)