Unable to upgrade Fortigate Firmware to 7.2.4

[kumarmt]

I am currently experiencing issues while attempting to upgrade the Fortigate firmware to version 7.2.4. The upgrade is failing both through the GUI and TFTP methods. The original firmware version is 7.0.10. However, when attempting to upgrade to random version 7.2.6 or downgrade to version 6.4.14, I can successfully perform the upgrade or downgrade using TFTP. If anyone has encountered the same issue and has found a solution, please let me know. The model of the Fortigate is 80F. I wanted to upgrade to 7.2.4

Booting OS...
No default firmware.
Error: Default firmware boot failed!!!
  Switch to BACKUP after 31 seconds. Press any key to stop.
FOS boot failed. You may try backup.
  Please power cycle. System halted.
  System will auto-reboot after 59 seconds ('CTRL+D' to reboot immediately).

resetting ...


FortiGate-80F (05:42-06.01.2023)
Ver:05000100
Serial number: FGT80FTK23045999
CPU: 1200MHz
Total RAM: 4 GB
Initializing boot device...
Initializing MAC... NP6XLITE#0
Please wait for OS to boot, or press any key to display configuration menu...

[C]: Configure TFTP parameters.
[R]: Review TFTP parameters.
[T]: Initiate TFTP firmware transfer.
[F]: Format boot device.
[I]: System information.
[B]: Boot with backup firmware and set as default.
[Q]: Quit menu and continue to boot.
[H]: Display this list of options.

Enter C,R,T,F,I,B,Q,or H:

Please connect TFTP server to Ethernet port 'WAN1'.

MAC: 74:78:a6:e2:86:4e

Connect to tftp server 192.168.1.100 ...


###########################################################################################################################################################################
Image Received.
Checking image... FOS signature Verification OK.
Fatal error: Loading FOS fails!
  Please power cycle. System halted.
  System will auto-reboot after 0 seconds ('CTRL+D' to reboot immediately)....

resetting ...


FortiGate-80F (05:42-06.01.2023)
Ver:05000100
Serial number: FGT80FTK23045999
CPU: 1200MHz
Total RAM: 4 GB
Initializing boot device...
Initializing MAC... NP6XLITE#0
Please wait for OS to boot, or press any key to display configuration menu...

[C]: Configure TFTP parameters.
[R]: Review TFTP parameters.
[T]: Initiate TFTP firmware transfer.
[F]: Format boot device.
[I]: System information.
[B]: Boot with backup firmware and set as default.
[Q]: Quit menu and continue to boot.
[H]: Display this list of options.

Enter C,R,T,F,I,B,Q,or H:

Please connect TFTP server to Ethernet port 'WAN1'.

MAC: 74:78:a6:e2:86:4e

Connect to tftp server 192.168.1.100 ...


########################################################################################################################################################################
Image Received.
Checking image... FOS signature Verification OK.
Fatal error: Loading FOS fails!
  Please power cycle. System halted.
  System will auto-reboot after 0 seconds ('CTRL+D' to reboot immediately)....

resetting ...


FortiGate-80F (05:42-06.01.2023)
Ver:05000100
Serial number: FGT80FTK23045999
CPU: 1200MHz
Total RAM: 4 GB
Initializing boot device...
Initializing MAC... NP6XLITE#0
Please wait for OS to boot, or press any key to display configuration menu...

[srajeswaran · Accepted solution]

This may be matching with https://community.fortinet.com/t5/FortiGate/Troubleshooting-Tip-Unable-to-boot-the-firewall-or-load-...

[AEK]

Which image file name are you using?

[kumarmt]

When uploading firmware via TFTP, i changed the firm image name to "image.out" allowed for a successful upload but failed during the upgrade process(image actual name was "FGT_80F-v7.2.4.F-build1396-FORTINET.out", "FGT_80F-v6-build1263-FORTINET.out"and i downloaded it from fortigate official page). This failure was due to a security level restriction. To address this, I downgraded the security level to 0, successfully upgraded the firmware to version 7.2.4, and then reverted the security level back to 2 after the upgrade was completed.

Is there any reason why specific firmware was not accepting by fortigate on level2 security?

Thank you

[kumarmt]

Thank you It works perfectly.