I have several students who get a blank screen when they access ai2.appinventor.mit.edu using Chrome on Chromebooks.
I started about 2 weeks ago. I am not able to reproduce this on desktop or laptop computers.
The page appears to load, but nothing is displayed.
Things I've tried:
Clearing browsing all data
Restarting the Chromebook
Forcing re-login (via ai2.appinventor.mit.edu/login)
ai2.appinventor.mit.edu is whitelisted
they get the gray screen at http://code.appinventor.mit.edu/ too