I upgraded a RB922UAGS from 6.49.6 to 7.2.1 without any apparent problems. However, the new ROS stops forwarding packets about 1 min after reboot. It happens after every reboot. Downgrade to 6.49.6 solves the problem. The RIP panel in 7.2.1 is completely messed up and I cannot check to see if the RIP configuration has been transferred correctly from the previous version. Any help would be appreciated.
The setup is the simplest you can have. A pair of RB922UAGS's in AP/station modes, just to forward packets. The router I am referring to is the AP. I haven't upgraded the station yet as it is remote.

Thanks a lot kanena. Your answer helped me solve the problem