AP1231G-E-K9 was converted to a thin client AP to be managed on a controller.
After a 'succesfull' conversion, the AP did registered with the controller, but since it's located at a remote site, it was be be coverted run HREAP. The AP is connected on a port that is in a trunk port to carry multiple vlan so it can support multiple SSIDs, but for some reason, when you select the AP mode, the HREP option is not there.. Follow the same procedure to convert the others with no issue like this.. Under the IOS image of the AP ( as reported by the controller ) it reads correctly 12.4(18a)JA2