Ensure TCP port 443 and UDP ports 27015–27030 are open in your firewall or router settings. If the error persists, try whitelisting RelicCoH2.exe in your antivirus software or temporarily disabling it to rule out a software block.
"The match you are trying to join no longer exists." company of heroes 2 match no longer exists
A Company of Heroes 2 Battle Retrospective Ensure TCP port 443 and UDP ports 27015–27030
Sometimes lobbies appear in the list but are no longer active on the server. company of heroes 2 match no longer exists
Right-click Company of Heroes 2 in your Steam Library > Properties > Local Files > Verify integrity of game files... to fix corrupted data.