$ flatpak run com.danplanet.chirp
Traceback (most recent call last):
  File "/app/bin/chirpw", line 131, in <module>
    from chirp.ui import mainapp
  File "/app/lib/python2.7/site-packages/chirp/ui/mainapp.py", line 26, in <module>
    import gtk
ImportError: No module named gtk

Nothing other than the version update has changed on my side. 

When I reinstall the previous version it works but still has some worrisome output:

 flatpak run com.danplanet.chirp
WARNING: python-future package is not available; chirp.drivers.ga510 requires it
WARNING: python-future package is not available; chirp.drivers.tk8180 requires it
Gtk-Message: 11:29:40.794: Failed to load module "pk-gtk-module"
WARNING: Icon  not found

Thanks,

Richard