I have searched for the error but didn't find any solution.
CampaignOperation operation = new CampaignOperation();
operation.OperationType = "CREATE_CAMPAIGN";
operation.@operator = Operator.ADD;
operation.operand = campaign;
CampaignOperation[] operations = new CampaignOperation[] { operation };
CampaignService campaignService = (CampaignService)user.GetService(AdWordsService.v201409.CampaignService);
campaignService.RequestHeader.clientCustomerId = ConfigurationManager.AppSettings["ClientCustomerId"];
CampaignReturnValue retVal = campaignService.mutate(operations);
When I tried to execute the last line "CampaignReturnValue retVal = campaignService.mutate(operations);", It gives error "OperationAccessDenied.ADD_OPERATION_NOT_PERMITTED @ class campaignmgmt.campaign.MutateAction (ADD) requires CREATE_CAMPAIGN" .
Please help me to resolve me this issue.