Python Add-ins don't seem to work for us since we upgraded from Windows 7 16 bit and ArcGis 10.1 to Windows 7 32 bit and ArcGis10.2. I even created one from scratch without adding any code and when it loaded, it showed up typical of a Python syntax error (with an x where the icon should be and the word "Missing" where the name should be). Custom toolboxes work fine. What gives?