Valheim beta is regularly updated, this goes for both server and client. The client is usually updated automatically via Steeam, however the dedicated server is not. When the versions mismatch, ie: the server is behind; clients can no longer connect to the server.

Updating the server to the latest beta is easy, yet manual. I've written a few scripts to take care of this process. It could be improved in many ways, but it works so why bother.

Note: This procedure requires steamcmd

1) Create a start-script for Valheim, mine is called and is placed with the binary:

export templdpath=$LD_LIBRARY_PATH
export SteamAppID=892970
echo "Starting server PRESS CTRL-C to exit"
./valheim_server.x86_64 -name "valheim" -port 12345 -nographics -batchmode -world "worldname>" -password "password" -public 1
export LD_LIBRARY_PATH=$templdpath

2) Start a screen named valheim by running screen -S valheim

3) Run to start the dedicated server and detach from the screen

4) Create a new script called with the following content:

echo "Sending Control+C to $VALSCREEN"
screen -S $VALSCREEN -X stuff $'�03'
echo "Sleeping 10 seconds, let Valheim server shut down..."
sleep 10
echo "Sleep done"
echo "Running update check and install..."
/bin/bash /home/aners/valheim/
echo "Update check and install complete, sleeping 5 seconds"
sleep 5
echo "Starting Valheim-server"
screen -S valheim -X stuff 'sh /home/aners/valheim/'`echo -ne '�15'`

5) Create a crontab for the script with a runtime of your chosing

Mine looks like this:

# m h  dom mon dow   command
0 5 * * * /bin/bash /home/aners/

Every morning, my Valheim server is stopped, updated and restarted.