Updaing UDF field using Taleo Web services

Summary

Getting error while trying to update the UDF or LUDS value using Taleo web services

Content

Hi All,

I am trying to update the UDF value using Taleo webservices but i am getting the below error message.

"UDFs" is not a valid model entity for this version or the required access type for this operation cannot be satisfied.

i am using Update method on Requisition web service and current version is 14B. 

using the same code i am able to update the value in delivered field.

Can someone please help me whether it is possible or not ?

Thanks & Regards,