Extra_english.lang file aint working

[Khyrpa]

You can't activate particle effects like this:
SetEntityActive("ParticleSystem_1" , true);

You have to use area (where you want it to appear) and:
CreateParticleSystemAtEntity(string& asPSName, string& asPSFile, string& asEntity, bool abSavePS); (check this at script functions wiki)

I assume "door_open_hall_key" is an script area?