Server list empty

This article suggests common troubleshooting steps if the in-game server browser is not showing any servers.

Resetting filters

If your filters are highly specific there might not be any servers matching the criteria. When an empty search is returned there should be a "Reset" button in the middle of the screen. Alternatively one of the easiest filters to miss is if some text is in the "server name" text field.

Checking game version

Are you on a different Steam beta branch? This article explains how to check if you are on a different beta version and how to opt-out. In general there are very few (if any) servers hosted on non-default versions.

If there has been an update or a rollback while the game is running all of the servers may have already changed versions. If so, there should be a notification on the main menu, in which case closing the game will allow Steam to update it.

Unblocking firewalls

If you have a firewall enabled it may be blocking the connection to all the servers. The way the server list works is Steam provides the IP of each server, and then your client contacts each one to ask for some basic details. Sometimes the firewall prevents contacting all these servers at once.

On Windows you might need to allow Unturned in Windows Firewall. The installer should have done this automatically though.

For third-party firewalls you will need to refer to their troubleshooting guides for details on how to allow the game traffic through.