I just put together a streets and a buildings set, including the 15 pairs of double doors that come with them. Now my problem is that the majority of them refuse to stand properly, instead falling towards the end with the clip indention. I.e. they lean towards the middle, rather heavily.

Anyone has any good ways to fix this?
Weighting them down maybe? Or does this require some sort of adjusting on the little stand element?

My current idea is to glue something thin but heavy on the underside of the door, but I'd prefer to wait and listen to suggestion then. I didn't find anything about this by using the search function either so I assume the solution might be obvious and I'm just missing it.

I have not had this issue at all which makes me think it might be placement of the clip on each door. Try that out and let us know.

I tried to fiddle with the bits.
It appears that if the little clip lies flat with the base of the door they stand better but are still prone to falling over constantly with the slightest bump of the build. And since this is meant for RPG sessions bumps are to be expected.

Additionally, I couldn't get all of the little clips to be flush with the bottom of the door, often because the bottom of the door itself is not flush - specifically the little nub is often a bit too long. This seems to be mostly on the street doors (I had the most problem with the street elements so far).

Might need to work on it with a modelling knife.

I wonder if some quick work of those nubs will do the job. Seems likely to me.

Alright, got it all fixed today.
For people who have this problem in the future:

1) Trim the nubs so the door's lower edge is flush with your table, if it's too long (and a lot of them were) the door will rock back and forth.

2) Make sure the little clip is on level with the lower edge, if it doesn't go all the way in it's easier to lengthen the slot (with a hobby knife) on the door than mess with the support clip.

3) If all else fails glue the support clip to the door and bend it slightly so that the clip and the door's lower edge form a Y like shape.

Glad you got this worked out and thanks for the tips for future posters.