The error you describe is shown when the model contains entities with properties of the following types:
So in order to generate WCF Data Services (Astoria 1/2) you have to check manually each property of all entities, and if there is a property with unsupported type, you have to change it. For instance, change all not supported integer types to Int32 or Int64 and Char to String.
If you have any other problems or concerns, please do not hesitate to contact us again.
the Telerik team
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