This FDT version offers new Quick Fixes for some project/classpath problems inside the Problems view.

These new Quick Fixes are available via right click or Ctrl-1 (Cmd-1):

This Quick Fix will remove classpath entries referring to missing SDK SWCs:

For the other Air Project problem Project Air SDK Version 22.0 does not match descriptor Air SDK Namespace 21.0 this Quick Fix is available:
This Quick Fix sets the descriptor namespace to the Air SDK version for each selected problem of an Air Properties profile.