You may use FMP16 (FMPA16) to develop. Just be aware of the changes made.
See if this helps:
In addition the "New Features" in FMP16 help:
I try to open the version for development to match a client's. If I cannot, I'm very aware of changes between (among) any versions.
And after development, testings are supposed to be made with the customers filemaker version and closer environment .