If the AP state is ver-mismatch or vmiss, the software version of the current AP does not match that of the AC. The AC checks whether the AP version matches the AC version when an AP goes online. If the AP version does not match the AC version, the AP is in ver-mismatch or vmiss state after going online. In this case, the AP cannot work properly. To rectify the fault, you must upgrade or downgrade the AP version to match the AC version.