This is a Verry Common Bug With Servers to get it back you Must

Go on to Game Tracker find Zarp 1 or 2 and Click on on Join
it will Re add it to the gmod surch list
and your back on

This is a Verry Common Bug With Servers to get it back you Must Go on to Game Tracker find Zarp 1 or 2 and Click on on Join it will Re add it to the gmod surch list and your back on