Android Studio - No Settings in Design Palette

Question

I recently invalidated caches and restarted Android Studio 3.1 as the upgrade from 3.0.1 to 3.1 gave me gradle build errors and another answer on here suggested that method.

My gradle will now build however the design palette doesn't show a preview, and the settings are all blank or null, or along those lines.

How do I get the design preview back?

Design Palette Screenshot

Tool Windows

Answer 1

Try:

View -> Tool Windows -> Preview

Try to rebuild or clean project. You can also restart android studio.