Contracts spwaning vessels on slopes steep enough to destroy them as soon as the player approaches.
This has bothered me for a long time and I really think it should be fixed because I think this can anger a player when it happens because it's just not the player's fault, at all:
There are several contracts that spawn a vessel which must not get destroyed or the contract fails and the player is penalized. But they will sometimes spawn these vessels at a surface location with a steep enough slope to destroy the vessel as soon as it gets unpacked. The moment the active vessel approaches within 200 meters, the target vessel starts responding to gravity, tumbling to its death when the player is still 200 meters away and can't do anything about it.
One particular contract with this common problem is RecoverAsset contracts with AcquirePart parameters.
The only thing "wrong" the player did was get within 200 meters of the part (which you have to do to retrieve it). After that everything that causes the contract failure is the game's fault.
It should be possible for KSP to get an approximate terrain slope at the spot by taking a few sample terrain heights a couple of meters from the spot and using them to calculate the normal to the terrain. If that spot is too steep, roll the dice again and try another spot.
I'm not even saying don't put it on hills. A bit of slope is a fun challenge. But I've seen it spawn things on crater walls more than 45 degrees sloped where nothing would possibly stay in place when you put it there.