There are two reasons when AT+WOPEN=3 return you an error (specifically +CME ERROR: 532)
- When the Open-AT application is active and AT+WOPEN=3 command is given.
- When there is nothing to erase in the A&D memory (i.e. the memory is already clear).
I think that in your case, the A&D memory contains nothing to be erased. This can be the reason why you received ERROR when you executed AT+WOPEN=3 command. Also enable the +CMEE error codes to check if you receive a +CME ERROR: 532 or something else.
One of the cause of this problem can be that you have executed your application which writes to A&D storage in debug mode of execution. In debug mode, the data is not actually written in the A&D storage. Rather, it is written in files present in the /rte/objects directory in the folder containing your Open-AT application.
This can be one of the reason that you received ERROR in response to AT+WOPEN =3 command.
Open AT Fan.