With the release of Revit 2015, you may be thinking about what needs to be done to get your 2013 and 2014 API programs working in 2015.
This video looks at some parts of the API that were marked obsolete in 2014 and removed in 2015. In upcoming posts I will show how to update projects like this so they can support multiple versions of Revit.
Boost Your BIM 
[…] https://boostyourbim.wordpress.com/2014/04/14/upgrading-your-api-applications-to-a-new-revit-version […]
I see there are two output plugins 2014 and 2015 from your solution. But I have a question that could we have only one output plugins which support both Revit 2014 and 2015?
Hi Ronan
Here’s a newer post on this topic. If there are no changes to the Revit API being used by your code then you could use a single DLL for multiple versions. I always build separate DLLs for every version and then use https://www.advancedinstaller.com/ to install the appropriate DLL for each version of Revit.
Harry