You need to debug your server. I would first disable/remove metamod from liblist.gam (revert to the original) and see if that fixes it. If it does then enable metamod but disable AMX Mod X and try again. If it does then you enable AMX Mod X but disable all 3rd party plugins and try again.
When the step at which you are no longer able to join the server tells you what is causing the issue (more than likely).
That server is Non-Steam and is running SXE or whatever it's called. Either of these is likely a cause.