I had a similar issue when trying to launch ARK from the web interface of our server. It appears that while my local game files are updated for the Love Evolved event and update that dropped today, most servers have yet to be updated with the same files. It's just a matter of waiting for them to update now. I had also tried logging in via Steam and our server was not listed. Hopefully the updates will be pushed out quickly. Here is a thread written by a moderator on the topic...
When will my ARK server update when ARK has an update? [ALL platforms]