Python state files should set the backwards compatibility version
If a python state file is written out and then loaded into a newer version of ParaView, it will fail unless the user edits the state file to add the compatibility version. All that has to be added is this:
import paraview paraview.compatibility.major = 5 paraview.compatibility.minor = 4
I think ParaView should add this automatically when saving out a Python state file so that the state files are forwards compatible with newer versions (until those backwards compatibility options are no longer supported).