Can't connect to friends GMOD server because of an error

I was playing GMOD with my friends when suddenly the game crashed. Since the crash, I can’t join the server or any multiplayer game. Here is a link to a screenshot of the error message:

Maybe the map file has either got corrupted or you have a different version of the map with the same name. What you should do is delete the map file, by going to <GMOD ROOT FOLDER>/garrysmod/download/maps/ and then finding the map file, deleting it and rejoining.

[editline]29th July 2017[/editline]

Then, in that case the map will be redownloaded and it will have the same version as the servers.

OK, I will try that. I will keep you updated on what happens.

[editline]29th July 2017[/editline]

Yay! This has fixed the issue. Thank you very much for helping :smiley: