Try clearing your download and downloads folders.

..\steamapps\common\GarrysMod\garrysmod\download\
..\steamapps\common\GarrysMod\garrysmod\downloads\

This will force you to download all server files again but could resolve your issue if it similar to an old issue that used to affect people.

It's also possible that there are connection issues with the EU host currently as there have been issues for a while now. If this is the case all you can do is wait and hope it resolves itself.

Try clearing your download and downloads folders. [b] ..\steamapps\common\GarrysMod\garrysmod\download\[/b] [b]..\steamapps\common\GarrysMod\garrysmod\downloads\[/b] This will force you to download all server files again but could resolve your issue if it similar to an old issue that used to affect people. It's also possible that there are connection issues with the EU host currently as there have been issues for a while now. If this is the case all you can do is wait and hope it resolves itself.