If it's an apartment, it's a bug. Lockable doors are 2-way exits - for some reason, the "other side" was never set to mirror the "other other" side. Once you get out...using wish, and also bugrepping it..for future knowledge:
In most cases, if you see an open door in an apartment and it makes RP sense for your character to explore, CLOSE the door, then OPEN it - BEFORE you go in. This will usually reset the "other" side so it mimics the locked/unlocked status of the side you are coming from.
Definitely bug the exit though while you're waiting for an imm to get you out, or if you have an IC friend you can always way them to roleplay the situation. You'd still want to bug it though.
Ah, thanks Lizzie.
Actually, in some cases, if you close and then open, you'll find it locked when you try to open it.
Yeah that's why I said try it -before- you go in.
That way, in case it's supposed to be locked, and the bug is on the "open" side of the door rather than the "closed" side of the door, you're at least safe, and in the hallway where you should be anyway, you nasty stinkin lousy open-apartment-investigator! :)
There's a certain mansion in Allanak that had this problem on just about every door in the place. Most of them should be fixed now, however if you are in that place, a helpful email to your clan staff would probably do wonders, since I bet at least a few of them are aware of the problem already. :)