Hi everyone,
We've put out Review Board 3.0.15, which has fixes for avatars, emoji, repository access control configuration, custom extension-provided JavaScript handlers for review request actions, and more.
The biggest fix, though, is for a regression in Bitbucket. Yesterday, they turned off an API that we used, breaking the ability to validate or view diffs. Going forward, if you use Bitbucket, you'll need 3.0.15.
As for Review Board 4.0, we're nearly done with a major update to move to Django 1.11 (the reason for the delay), and should finally be in a beta state Soon™.