Hi,
I have test it with empty blocks only two button with default colour (background and text)
If I change theme, the application stops working immediately after installation. It works only if it is in classic theme.
When I use title invisible only text is invisible, gray box is still gray. In AI 2.45 was all box invisible.
If I use classic theme and primaryColor:none and primaryColorDark:none aplication stops after instalation.
Now I saw if I use ActionBar on screen1 gray box is invisible and theme works without any problem.
I test it in Samsung android 5.1.1
Generally, this is a great project :-)
Regards,
Zoran