Workspace is running an unsupported version of Rocket Chat

My RocketChat server has stopped responding to the Linux Desktop client and the web. The server was upgraded last week to 6.5.0 (along with the database). What do I do to get the server working again? … or will I need to investigate alternative chat solutions?

this may be fixed in latest client version?

fix: Supported version alert just close on button by @jeanfbrito in #2778