Having a Newline character in your WiFi name can disrupt all connections.
If you end a Phone's WiFi direct device name with a newline character, then the system comes down.
The person entering the phone name probably popped up the keyboard and after typing the name, hit the "return" button instead of the "Done" button. This added the non-printing character to the end of the name, and from that moment onward, whenever the phone connected with another phone via WiFi direct, it created a connection name that for some reason was capable of crashing any phone that was also doing WiFi direct stuff.
How to tell if you have done this by mistake:
- When your device name shows up on the WiFi direct connection page, it is trailed by an underscore
- The group name given to an existing connection ends with \n
- When you bring up the edit name box, there is a blank line under the actual name.