You need to migrate the code to the new API.
That is trivial.
First time migration, including some reading of 'What's New' information: 20 minutes, maybe.
Next time: less than five minutes.
Have you searched for an answer at all?
I must have answered this dozens of time already.
Surely some trace must remain somewhere?
http://thebuildingcoder.typepad.com/blog/migration
http://thebuildingcoder.typepad.com/blog/2014/04/whats-new-in-the-revit-2015-api.html
Have fun!
Cheers,
Jeremy