I know that a cutoff date of 28 June 2017 for API v1 is what is stated on your Developer Blog here...
https://blogs.dropbox.com/developers/2016/06/api-v1-deprecated/
But, it seems as though there are some problems with the current version of the API v2 Objective-C SDK, for example the in ability to cancel requests...
https://github.com/dropbox/dropbox-sdk-obj-c/issues/76
As as everyone here knows: the v1 to v2 transition is a very sizable programming and debugging effort. I am concerned that I will not be able to migrate my iOS app to API v2 and thoroughly complete testing in time for the shut off of v1. Note that my iOS app has been running flawlessly under v1 for over two years.
Is there any possibility that the v1 shut off date can be moved back to allow us (and you) more time to get this transition right?
Thank you.