Cannot get my VS2013 extension to run in VS2015

I have a very useful extension (to me) which adds syntax coloring and a command to Visual Studio when opening a prolog file. I have it working since VS2010 but now I moved it to VS2015 and nothing happens, I don't see anything strange in the ActivityLog.xml and every breakpoint I set does not get hit.

Is there anything I should be checking for? any hints?

Thanks

http://about.me/sebagomez