Hi,
The same ad param cannot be specified in multiple operations in the same API request. When you include the same combination of criterionId, adGroupId, and paramIndex in more than one AdParamOperation in the request, you'll encounter AdParamError.AD_PARAM_CANNOT_BE_SPECIFIED_MULTIPLE_TIMES error. Could you check the request to see if there is more than one instance of the same criterionId, adGroupId, and paramIndex combination? If you have the SOAP request and response log for the operations which encountered this error, please send them over via the Reply privately to author option so I can take a look.
Regards,
Shwetha, AdWords API Team.