Yes that absolutely can cause problems so you can try disabling FT.

CSCwa73906 should have been fixed in 17.9.5.205 so best to open a TAC case if it bothers you. But either way since these messages are cosmetic you can just ignore them.

@yaya not sure how you linked those debug messages to rogue APs? > from our point of view, these are not harmless...CSCwa73906 is quite clear "These messages are considered to be normal and can be ignored - they will be logged immediately after a cli...

What's the exact version running on the AP @pengus If it's 17.9.5.47 or later 17.9.5 version (which is supposed to have the fix for CSCwa73906) then best to open a TAC case.

Hi @Gehrig_W your problem is not that 9800 17.12 does not support ISE 2.4 - it's that ISE 2.4 is END OF SUPPORT!  So really you're in exactly the same position with 17.9 now.https://www.cisco.com/c/en/us/products/collateral/security/identity-services...