Using fetchXml the query is not working for few entities.
We are using the following URL to get the data.
xxxxxxxx.crm.dynamics.com/.../optionsets?fetchXml=<fetch><entity name="optionset"><all-attributes/></entity></fetch>
It gives the error:
{"error":{"code":"0x80040800","message":"The 'RetrieveMultiple' method does not support entities of type 'optionset'. MessageProcessorCache returned MessageProcessor.Empty. "}}
We are using the above URL as a get query from Java program.