theres so many errors

I would suggest reporting the error to the gmod team, they tend to be pretty responsive on discord.

Yes, I agree your point of view, but currently the workshop is very unstable some players won't be able to download contents due to an known error "0 byte downloaded ..", so, I'm using both workshop/fast dl in my server

Hi, I don't recommend putting maps in fast-dl for that very reason.
Easier for everyone to just use the workshop version, it's a relatively small file after all.

Thanks for your map, it is good, but would it be possible that you rename the name of the map, to mu_theater_v1 for example, because this is doing issues in my murder server with fastdl, because other players do have the old version, (mu_theater) it does say to them "map is differing from the server"

This map is quite scary

good