You won’t be able to start a game on an L4D server, which is outdated!
Here the update-procedure for super admins, that have access via ssh:
Connect as user Steam !
(otherwise you may get “Loading Steam API…threadtools.cpp (2420) : Assertion Failed: Permission denied.””
# Steam@210414_l4d_server1:/$ su -l Steam -c cd /home/Steam && ./steamcmd.sh +force_install_dir /home/Steam/l4d +login anonymous +app_update 222840 +quit