I've got some software I've written that I'm trying to recompile for Arc 10.3. The old COM registering software compiles ok, but I've been having problems with the newer addins I've written for ArcMap. If I load them up (in Visual Studio 2012) and compile them I don't get any errors but it doesn't actually make the output .addin file I'm expecting. I've tried adjusting different values in the adding config file but it doesn't seem to help. I can port the code across if I make a new addin project and move the source files over but this is a lot more time consuming than I'd expect. Is there a simple way to update my addins?