In your output to me your FWM process is terminating. The best bet is really to upgrade to 77.30 because if you had to call support for your problem right now its not supported. Why its terminating though IMHO is not worth worrying about because likely a fresh install of 77.30 will fix your problem. 77.20>>>77.30 is an easy upgrade. 77.30 should work with all of your earlier FW releases unless your firewalls are super old.
FWM 0 T 0 [08:44:43] 6/11/2017 N fwm <--- shows FWM terminated
Looking at the 77.30 release notes these GWs are still able to be managed from 77.30
NGX R65 R70, R70.1, R70.20, R70.30, R70.40, R70.50 R71, R71.10, R71.20, R71.30, R71.40, R71.50 R75, R75.10, R75.20, R75.30, R75.40, R75.45, R75.40VS, R75.46, R75.47, R76, R77, R77.10, R77.20, R77.30.
However, I would recommend you consult 77.30 release notes and validate for yourself.