amnesia level editor key for locked door problem

[OriginalUsername]

You shouldn't use void OnEnter(). Use void OnStart instead. I think that's the problem.
And you have to use level doors to change to other maps. Just click on the level door, click the entity tab, go to StartPos (Enter the name of your playerstart area in the other map). Click the '...' next to MapFile and select the map you want it to bring you to.
You could also use the ChangeMap command but using level doors makes more sense.
If you need help with commands, I'd recommend this site.

EDIT: And you used </LANGUAGE> in the beginning of your .lang file. Change it to <LANGUAGE>. And perhaps doing this: RemoveItem("monsterdoorkey_1"); could do something