| Description | This article describes useful information for when FortiAP-B, C, D, and S series do not come online on FortiGate 7.4.0, instead showing an 'Invalid FortiAP serial number' error. |
| Scope | FortiAP-B, C, D and S series. |
| Solution |
Some customers find that after upgrading FortiOS to v7.4.0, their FortiAPs B, C, D, and S series cannot go Online on FortiGate and therefore cannot be managed. An attempt was made to configure the SN manually following the Pre-authorizing a FortiAP unit instructions, but the error 'Invalid FortiAP serial number' appeared.
Check FortiAP and FortiOS Compatibility Matrix. This is also documented on the Release notes for FortiOS 7.4.0
As a workaround, the administrator can downgrade to v7.2.x or earlier to have these FortiAPonline on FortiGate.
Downgrade the FortiGate by following the downgrade instructions in the administration guide.
It is strongly recommended to engage a Fortinet pre-sales contact to replace these models with newer versions as they will reach soon their EOS milestone or some already have. Find more details on these dates here: Product Life Cycle |
