problem using mergDropbox under 8.1.0. dp 3

[Ben Rubinstein]

I was using mergDropbox in iOS 7, before LC acquired the suite. I believe that 
I also had it working under 8.0.x, before the advent of the inclusions tab in 
the standalone builder (but can't now be certain - I've decided to stay on the 
bleeding edge for anything later than 7, and recently purged all my 
intermediate 8 versions. I can check if it becomes relevant.).

The same stack under 8.1.0 dp 3 is now failing to link to a dropbox folder. 
The call to mergDropboxSetup (in openStack) returns empty, as I'd hope; a call 
to mergDropboxIsLinked correctly returns false; however, a call afterwards to 
mergDropboxLink simply returns empty, where I'd expect it to throw up a 
Dropbox authorisation request.

Subsequent calls to e.g. mergDropboxLoadMetadata not unreasonably throw errors 
of the form
mergDropboxLoadMetadataError: Error Domain=dropbox.com Code=400 "(null)" 
UserInfo={error_description=No auth function available for given request, 
path=/, error=invalid_request}

Before I log this in the QCC, is there something straightforward that I need 
to do differently to make this work?

Many thanks,

Ben