We've run into an issue with setting up client's Easyblog for autoposting to Twitter. We haven't changed our process at all, so I looked into what might be causing the issue and I found this dev blog post: https://twittercommunity.com/t/action-required-sign-in-with-twitter-users-must-whitelist-callback-urls/105342
Essentially, Twitter is enabling callback locking just like with every other major social media platform these days. With this enabled, it's impossible to connect an application to Easyblog unless we whitelist a specific URL or URLs.
We could use a fix for this as soon as you're able.