Hi All
I've got myself backed into a corner with seemingly no way out. 
I upgraded my app to XF 2.0.0.6940, having previously installed Google Play Services (which is currently 27.0.0.0) to get GCM.
When I run on KitKat with a FormsAppCompatActivity, with the parent style for the app set to Theme.AppCompat.Light.NoActionBar, the app crashes with a NRE that references the "SetElement" method of the MasterDetailRenderer for the platform.
If I set the style to Theme.AppCompat.Light the Java layer throws an exception complaining that I shouldn't be asking for an ActionBar when there's one already set. The error message is a spectacular example of unclear writing, so I can't quite figure out from it what the correct incantation should be. Regardless, I don't have much control over what XF is doing in its internals anyway.
If I revert the main activity back to a FormsApplicationActivity, the app crashes again in SetElement with a NRE.
It appears to run OK with the AppCompat layer when I start it on Lollipop.
I cannot allow the app to be released as it now stands.
Can anyone please give me some clues about how to fix the problem and get the app running again? I'm getting to be quite apprehensive about upgrading XF lately as each update seems to break more than it fixes.