We recently upgraded TFS 2010 to the release of TFS 2012 RC. Everything was easily updated, with the exception of our assemblers. Does anyone know where to find the logs that show why assembly controllers / agents work?
We have a single server configuration where TFS, SharePoint, SQL2008 R2, Build Controller and Build Agent are in the same window.
All new features seem to work with the exception of assemblies. When the assembly component starts, it initially shows the status of the controller and agent as a green arrow, but after 30 seconds it goes into the Red Box state.

Then, if you click on the "Details" link to find out what the error is, I get a popup with error 500: 
Any help on how to diagnose or find error logs, etc., would be appreciated.
source share