SAPUI5 Mobile - Gateway - OData Model Update fails

Hi everyone,

i´m trying to update an entityset from my SAPUI5 Mobile application but it dont works. I have created a gatewayservice

and redefined the update method.

The key of my entityset is a GUID and here is my problem. When i try to send an update with the GUID as key i get an error.

I tried it with the mozilla rest client like that:

(PUT) http://server:port/sap/opu/odata/sap/Zxx/Zexample(binary'0050568E41441EE2A0CEF4856C90D160')

and i get the status code: 415 Unsupported Media Type. If i try to read the entity with the same url (get) it works fine.

Does anybody know how to solve that? I would be very gratefull.

Thanks,

Waldemar