In the main menu of Garry's Mod, open the "Options" window, and in the "Keyboard" tab, press the "Advanced..." button. Make sure the "Enable developer console" box is checked in the window that pops up and press "OK". From this point on, you should be able to open and close the console with the ~ (tilde) key, which is usually in the top-left corner of your keyboard.

If you are experiencing any Lua errors, they will appear as either yellow or blue text in the console. You can copy the error message and paste it back here.

[gmDoom] lua/doom/hooks.lua:24: attempt to call field 'GetTicTime' (a nil value)
1. v - lua/doom/hooks.lua:24
2. unknown - lua/includes/modules/hook.lua:82

That's odd.. Is that the only error you're getting? What color is it?

It was blue the only thing that was working was the hud. I have installed a cyberdemon addon on an older garrysmod at it's still there but not working

I don't know if that has anything to do with it.

That cyberdemon addon, is it a DOOM 1/2 cyberdemon, or a DOOM 3 cyberdemon? If it's a DOOM 1/2 cyberdemon, you need to delete the "Classic DOOM" folder in your addons folder - it's something I wrote before gmDoom, and it will cause conflicts if you still have it installed.

Yeah it's a DOOM 1/2 Cyberdemon

I couldn't find the folder so would it be safe to delete everything in the addons folder and redownload the addons later?

Probably. If you want to be safe and keep a backup, you can rename the addons folder to addons2 or something like that.

Okay I'm gonna re install gmDOOM and try it out

The addon is still there

I finally found it deleted it and now it works :D thanks for uploading this and thanks for the help.

i cant find the advanced button on keyboard it has dissapeard for me D:

引用自 loosecannon51：

i cant find the advanced button on keyboard it has dissapeard for me D:

T_T In your options menu maybe?

no really i looked isnt advanced in the bottom?
and also i play MGS aswell XD