AdropErrorCode

Code	Message	Description
0	OK	Success.
4000	ERROR_CODE_INVALID_UNIT	Ad unit ID is not valid.
4001	ERROR_CODE_AD_INACTIVE	There are no active advertising campaigns.
4002	ERROR_CODE_AD_NO_FILL	Unable to receive ads that meet the criteria. Please retry.
4003	ERROR_CODE_INVALID_PARAMS	Parameters are not valid.