| Symptom | Likely Cause | Resolution | |---------|--------------|-------------| | High memory (70%+ idle) | flow-based inspection + WAD memory leak | Upgrade to 7.2.11+ or disable log flooding | | IPsec tunnel flapping | FortiOS 7.4.0–7.4.3 bug | Upgrade to 7.4.4+ or roll back to 7.2.x | | GUI slow / unresponsive | Database corruption after upgrade | Factory reset → restore config (not from backup image) | | FGFM tunnel down (FortiManager) | Firmware mismatch with FMG version | Align FMG build to support 60F’s FortiOS |
This usually happens if you skip upgrade steps (e.g., going from v6.4 straight to v7.4).
Jumping directly from v7.0 to v7.4 will likely corrupt your configuration or cause boot loops. You must follow the "Upgrade Path" ladder.
Before proceeding, please note two critical points regarding the FortiGate 60F:
The shines on FortiOS 7.2.11 (or latest 7.2.x patch). Avoid 7.6.x entirely, and only run 7.4.x if you need ZTNA proxy or advanced SASE features — but monitor memory weekly.