I have an addin that I've been maintaining with Visual Studio 2010 Express for quite some time with no issues. Recently my computer was replaced and Studio 2012 Express was installed. Since that time when I build the addin everything is created except for the .esriAddIn file which is necessary to run the addin with the changes. After looking at the ArcObjects (VB.NET) system requirements I noticed that the only Express version listed was 2010 so I assumed 2012 was the culprit and had our IT department roll me back to 2010. Unfortunately that didn't solve the problem and I have been searching for a solution with no success. Anyone have any ideas why every file is built except the .esriAddIn file?