That was my experience too. Still pretty scary when you have that much money in the sky. DJI saying "sorry - just kidding"Simply ignore and the message will go away.
I had a large yellow rectangular box appear with message critical error land immediately. Landed took off again - message battery level critically low (battery was 100%). Landed, tried again - distance away measurement bottom left of screen - blank. Retried - message - gimbal not connected - no video.
I've since downgraded to 1.8. So how do I know when to trust that DJI has fixed the problems AND beta tested their fixes. Several of my friends have stopped doing upgrades until more wealthy people confirm that the fixes and upgrades are trustable. Not a good day for DJI.