Unable to load maplist.txt

Hey there

When I start up Gmod, this message pops up in the console:

GetAllManifestFiles:Unable to load maplist.txt

When I try creating a single player game, all the maps I have in the maps folder, except from the original ones, is not in the map menu. If I create a game with an original map, I only have the default tools/NPC’s/entities, and pretty much all addons are gone.

Can anybody help me?

I get the SAME message! And I can’t get any servers!

§ame here, Please help !!
I cannot join any server since there is no server list…
I also get that same error message !