Not sure if the Admins saw this, I sent them a message for you.
https://forums.projectceleste.com/members/luciano.1/
https://forums.projectceleste.com/members/ryddag.2/
https://forums.projectceleste.com/members/cad39again.3/
1: Try a fresh install. Try installing via steam if you did the direct download, try installing via the direct download if you installed via steam.
2: Once you get the launcher up, use the "game helper" tools to fix your Windows Firewall ports.
3: In order to play coop, you can change your...
Reminder: if you are on the same lan network (ie. in the same house), you MUST set your launcher to LAN in order to play with others.
It will ALWAYS time out if you do not have this set.
Sadly, this does mean you and your roommate cannot play with your friend online.
They feel like legacy items from back when this game had tens of thousands of active users.
Pretty sure the devs aren't removing chat channels, as their focus is on adding content.