Troubleshooting Tip: A valid upgrade path cannot be determined for manually uploaded firmware

This is because FortiGate will access the FortiGuard server to check the valid upgrade path.

• If the FortiGate does not have internet access:

When upgrading with a manually uploaded image to the FortiGate, a message will be shown:

Example from v7.2.x:

Example from v7.4.x:

If the correct upgrade path is followed and the image is valid, the message can be ignored, and the upgrade can proceed.

Check the upgrade path using the Upgrade Path Tool or the Fortinet Support Portal.

Refer to this article: Technical Tip: How to verify FortiGate Upgrade path to upgrade the FortiGate to a higher Firmware Version for more details.

• The same message shown in the above snapshot is also displayed if the FortiGate cannot resolve the FQDN due to a DNS issue/reachability. 

Special note: 

In the FortiGate virtual machine in v7.4. x and v7.6.x, even though FortiGate can retrieve the correct image list from the command below:

kenobi-kvm56 # diagnose fdsm image-list | grep 7.4
07004000FIMG0013704009 v7.4 MR4-GA-M P9 b2829 (upgrade)
07004000FIMG0013704007 v7.4 MR4-GA-M P7 b2731 (downgrade)
07004000FIMG0013704006 v7.4 MR4-GA-M P6 b2726 (downgrade)
07004000FIMG0013704005 v7.4 MR4-GA-M P5 b2702 (downgrade)
07004000FIMG0013704004 v7.4 MR4-GA-F P4 b2662 (downgrade)
07004000FIMG0013704003 v7.4 MR4-GA-F P3 b2573 (downgrade)
07004000FIMG0013704002 v7.4 MR4-GA-F P2 b2571 (downgrade)
07004000FIMG0013704001 v7.4 MR4-GA-F P1 b2463 (downgrade)
07004000FIMG0013704000 v7.4 MR4-GA-F b2360 (downgrade)

kenobi-kvm56 # diagnose fdsm image-list | grep 7.6
07006000FIMG0024006006 v7.6 MR6-GA-M P6 b3652 (upgrade)
07006000FIMG0024006005 v7.6 MR6-GA-M P5 b3651 (upgrade)
07006000FIMG0024006003 v7.6 MR6-GA-F P3 b3510 (downgrade)
07006000FIMG0024006002 v7.6 MR6-GA-F P2 b3462 (downgrade)
07006000FIMG0024006001 v7.6 MR6-GA-F P1 b3457 (downgrade)
07006000FIMG0024006000 v7.6 MR6-GA-F b3401 (downgrade)
07004000FIMG0024004006 v7.4 MR4-GA-M P6 b2726 (downgrade)
07002000FIMG0024002010 v7.2 MR2-GA-M P10 b1706 (downgrade)

However, 'image-upgrade-matrix' has an error from the following command, causing a GUI error to be displayed:

kenobi-kvm56 # diagnose fdsm image-upgrade-matrix
Result=Error.

BUG 1224484 has been identified for this error message, and this issue has been marked resolved in v7.4.10:2848, v7.6.5:3641, v8.0.0:0097.

Workaround:

The workaround is to upgrade the FortiGate-VM using the CLI command 'execute restore image management-station <image_id>'.

execute restore image management-station 07006000FIMG0024006005

For further steps to troubleshoot and update the FortiGate's list of firmware images and paths, see Troubleshooting Tip: No firmware available from FortiGuard under firmware management.

Related article:

Troubleshooting Tip: No valid upgrade path error when upgrading the FortiGate firmware