Thank you for reporting this. This issue was fixed in the upcoming 1.9.1 release.

Hello again. We wanted to give you a quick reminder that to efficiently investigate and reproduce your issue, we need you to submit the additional information we requested. If we haven't heard back from you with the requested information in the next 3 days, we will go ahead and close the issue.

Thanks for your feedback. In order to efficiently investigate and reproduce this issue, we are requesting additional information outlined below.

Could you please give us a dump file so that we can conduct further research?

Visual Studio now has an extension called Microsoft Visual Studio 2013 Feedback Tool, available on the VS gallery(<http://visualstudiogallery.msdn.microsoft.com/563d1003-f0ed-498f-8ef9-f8ee1aac39fe>)

The extension allows you to
1. upload files
2. collect trace and dump files
3. collect steps while you're repro'ing the issue
4. SQM logs about VS extensions installed
5. System details (in DxDiag output)

Please submit this information to us within 3 business days. We look forward to hearing from you with this information. If you require immediate assistance with this issue, please contact product support at http://support.microsoft.com/ph/1117.

Thank you for your feedback, we are currently reviewing the issue you have submitted. If you require immediate assistance with this issue, please contact product support at http://support.microsoft.com/ph/1117.

Note that this issue is reproducible in other ways, independently of whether or not Unity has "Auto refresh" enabled (Edit -> Preferences -> General); and of which Visual Studio run configuration is used. The issue seems to happen precisely when the debugger is attached during compilation, no matter how one gets to that point.