Issue while redefining BEx query in NW Gateway

Hi Friends,

I am trying to redefine a BEx query in Netweaver Gateway system using SEGW transaction, and MDX query option. I am getting the following error after step 2 (step 1 is selecting the catalog and query name, and step 2 is assigning model/service name)  :

I have already created one test odata service by redefining another query from the same system, but I was able to do it successfully. Any help on the error would be appreciated !