I am writing a custom Lightening connect connector. However, none of the classes in new DataSource namespace are available, I get the error 'Invalid class'. I have tried the code in a sandbox environment running summer 15 code, the same error exists in summer 15 sandbox also.

Any help on how to address this issue is much appreciated.

I am writing a custom Lightening connect connector. However, none of the classes in new DataSource namespace are available, I get the error 'Invalid class'. I have tried the code in a sandbox environment running summer 15 code, the same error exists in summer 15 sandbox also.

Any help on how to address this issue is much appreciated.