Drag/Drop feature in Android studio not working
the new version of android studio uses 2 xml files for each layout. One (e.g. content_main.xml) embedded in the other one (Activity_main.xml).you should open the content_*.xml and do the design in it.hope it helps.
In addition to Hamed's answer I also had to:
File > Invalidate Caches / Restart ...
I'm missing vim.
The drag and drop feature is not working in Android Studio.... I also wasted a lot of time searching...what fixed my problem was to select a Theme for the Activity.
The image below will make things clear.