General Error Handling
This is the start of your topic. The OTA Client shall be tolerant and behave appropriately (i.e., the OTA Client shall be able to continue to process operations and/or receive data normally) when receiving the Result Codes, ATT Application Error Codes, and ATT Error Codes defined in the OTA Service [1].
If the OTA Client reads a characteristic with Reserved for Future Use (RFU) bits that are non-zero (i.e., RFU bits in the OTA Feature characteristic), it shall ignore those bits and continue to process the characteristic as if all the RFU bits had been zero.