Thanks, that seems to have resolved that particular issue - mind you it seems a little long-winded compared to the old method and there doesn't appear to be anything in the documentation that suggests that's what you need to do. Not only that, but it's inconsistent compared to newFetchPersonRequest (where you can just pass in opensocial.IdSpec.PersonId.VIEWER).
I now seem to have run across another problem - I'm actually trying to retrieve the app data for the owner, but when I try to retrieve with an OWNER IdSpec (generated by either just setting the USER_ID or also setting the NETWORK_DISTANCE and GROUP_ID as per the breaking changes doc) I get the JS error 'MyOpenSpace.Group is undefined'. Trying to retrieve the app data using VIEWER (this is the canvas, so OWNER == VIEWER) yields different errors:
* Just setting the USER_ID, or setting the USER_ID, NETWORK_DISTANCE and GROUP_ID results in the JS error 'C is null'
* Setting USER_ID and GROUP_ID (to opensocial.IdSpec.GroupId.SELF) results in the JS error 'opensocial.IdSpec.GroupId is undefined'
Any thoughts?