Errors for everyone

I have a ttt server, but whenever someone connects or the round changes, everyone gets the following messages


Requesting 3 lua files from the server
ConVarRef ttt_time_limit_minutes doesn't point to an existing ConVar
ConVarRef ttt_round_limit doesn't point to an existing ConVar
ConVarRef ttt_zedtime_traitor doesn't point to an existing ConVar
ConVarRef ttt_zedtime_detective doesn't point to an existing ConVar
ConVarRef ttt_zedtime_enable doesn't point to an existing ConVar
ConVarRef gmod_physiterations doesn't point to an existing ConVar

I have zedtime installed. These errors cause some people to disconnect for too many lua errors. What is wrong and how do I fix it?