Troubleshooting Tip: Unable to change VLAN on D-link Switch (DGS -1510-52X & DGS -1510-28X)

In some situations, the switch is added correctly and shows no error upon performing the 'validate credentials' process. However, the VLAN does not change, either via policy or manually. 

Debug will show similar lines as below:

dlink-test#
yams INFO :: 2025-03-10 13:11:59:736 :: #536 :: Thread:https-jsse-nio-0.0.0.0-8443-exec-5 - SET =config vlan vlanid 140 add untagged 3
yams INFO :: 2025-03-10 13:11:59:736 :: #536 :: write = config vlan vlanid 140 add untagged 3
yams INFO :: 2025-03-10 13:11:59:736 :: #536 :: Thread:https-jsse-nio-0.0.0.0-8443-exec-5 - Command WAIT_FOR = #
yams INFO :: 2025-03-10 13:11:59:736 :: #536 :: TelnetServer:generateMatchingArray - #
yams INFO :: 2025-03-10 13:11:59:778 :: #536 :: TelnetSession.waitfor() ip = 10.76.0.204 num bytes = 149
yams INFO :: 2025-03-10 13:11:59:778 :: #536 :: Thread:https-jsse-nio-0.0.0.0-8443-exec-5 - Command WAIT_FOR returned:

[C[C[C[C[C[C[C[C[C[C[C[0Kconfig vlan vlanid 140 add untagged 3
^

Invalid input detected at ^marker

Solution:

execute enter-shell
Device -ip <Switch-IP> -setAttr -name FirmwareVersion -value DLinkSwitch313

This attribute resets on every reboot of the FortiNAC appliance.

For a permanent fix, upgrade to FortiNAC-F v7.6.3 or above.