• Your Rocket.Chat Experimental app version: 4.6.4
• Your Rocket.Chat server version: 3.1.1
• Device (or Simulator) you're running with: Android and iOS devices

The app crashes on connection, stack trace starts with

com.facebook.react.common.JavascriptException: TypeError: Cannot read property 'length' of null

This error is located at:
  in k
  in s
  in RCTView
  in Unknown
  in Unknown
  in S
  in RCTView
  in RCTView
  in o, js engine: hermes, stack:
getRoomAvatar@1:1525521
....

With Rocket.Chat server version 3.0.12 the app was working.
The older version of the app (4.5.1) works also with Rocket.Chat server version 3.1.1.

I suspect the change in #1958 is the culprit:

Screenshots of the full stack trace: