Null in Android Studio preview API version

Question

I upgraded from Android Studio 2.3 to 3.0, and now none of the previews are displayed in XML editors.

I see zero on the top line in the API level selector, and this does not allow me to select

Any possible solution for this?

I tried Invalidate cache and rebooted, but it doesn't seem to help.

Answer 1

Just click "Sync with gradle" and enjoy :)