Thanks for sharing your log message and explaining what changes you've made. Please re-enable the AP Conversion (LWAPP2SCG), and then try a factory default of your AP? I hope this will be your solution.
The message calls this a "ZD-AP" which tells us that it has been under control of a ZoneDirector (LWAPP). The rest of the message tells me that the H500 cannot connect to your SmartZone controller.
Otherwise, you would need to install the Solo/Standalone 104.0 firmware for H500, which can join either SZ or ZD (or run solo if not pointed to a controller by DHCP/DNS or CLI 'set' command).