Dropbox originally deprecated the Dropbox API v1 in June of 2016, with a final cutoff date of June 28th 2017. At the request of developers, Dropbox extended the cutoff date to September 28, 2017. Dropbox officially retired v1 last week.
Now, calls to v1 endpoints return the following 400 error:
Accordingly, any integrations or applications utilizing v1 will no longer function properly, at least to the Dropbox functionality. Those looking to migrate to v2 should check out Dropbox's migration guide.
As previously mentioned, Dropbox's aim with the move to v2 is to provide a consistent, simplified, and scalable platform for developers to leverage. Dropbox extended the original cutoff date, not because it believed v1 was the long term solution; but rather, Dropbox wanted to ensure that developers received adequate time to transition. v2 is the platform that Dropbox feels will take it to the next step in its roadmap, and now is time for developers to join Dropbox in that next step.