I changed both, ro carrier and ro operator to any other and I still get systemui fc. Tried TMO and my current carrier id.
For those who try this, if you get stuck in systemui fc loop, turn on airplane mode. That will stop it until you fix it.
Primary Phone: LG G2 CyanogenMod 11.
Tablet: Asus Nexus 7 ALL-F2FS Cyanogenmod 11.