We're currently experiencing issues with Posting, Following, and Unfollowing on Twitter.
We’ve already raised it at Twitter so we hope we’ll get our write actions (posting and following/unfollowing) rights back ASAP. It should normally not take more than one or two days.
In the meanwhile, you can still use our Buffer integration to continue posting on Twitter: https://help.socialbee.io/accounts-and-settings/buffer-integration
We’re really sorry for this inconvenience and we’re doing our best to get this solved ASAP.