What invalidates "before they spread" events besides letting the incident spread?

I have the challenge to "Defeat 6 Radroach infestations before they spread". Several times I have had Radroach incidents which spontaneously appear in a dweller-filled room (or due to a rush failure).

The dwellers defeat the RadRoaches before another room is affected ("before it spreads"), but the defeat does not register to the challenge. Why is this happening?

I have experienced similar disqualifications with the "Survive a Deathclaw incident without casualties" not registering to a challenge , even though I have lost no dwellers.

What causes this sort of incident to be disqualified BEYOND the obvious "letting the incident spread" to other rooms? I suspect one or more of the following actions could cause disqualification in the way I'm experiencing:

  • Moving dwellers to/from the incident to/from another room?
  • Moving dwellers between non-incident rooms during the incident?
  • Healing a dweller in the room with a stimpack?
  • Having pregnant dwellers abandon the room?
  • Having Coffee Break dwellers walk (run) through the incident room?
  • Changing a dweller's equipment during the incident?
  • Leveling or skilling a dweller during the incident?
  • Collecting a room's product during the incident?

Please explain what the unexplained "hidden" disqualifier(s) is.


From experience of playing the game myself, I can verify that this is a bug - though I cannot specify what may cause it.

The only requirements of this challenge is to kill the Radroaches within the room that they appear. If they appear in any other room during the incident, then you have failed. Those are the only parameters.

There are some possible bugs that may affect this, but from the current list of known bugs, nothing has yet been identified


I think I figured it out. (Not 100% sure though)

In order that the incident accounts to the counter these requirements have to be met:

  1. The radroaches/molerats may not spread to another room (obviously)

AND

  1. You have to send at least one dweller into the infestated room.

AND

  1. No dweller may leave the infestated room during the infestation.

The AND combination of point 2 and 3 means, that it only works in rooms that aren't completely manned by dwellers. There have to be at least one free spot in order to send a dweller in without another leaving the room.