This is the first time I’ve had this happen to me in 20 years, so I realize the likelihood of me simply not having found the exit is higher, but in the following game that I’ve created Catacombs Level 3 does not appear to have an exit to Catacombs Level 4.
https://i.imgur.com/LblnWWV.png
Looks like it should be on the upper left.
Weird.
Had a similar bugged map myself last night. Stony Field with no exit other than back to Cold Plains.
i have also had this issue, sometimes it will also not show the exit point. i have teled full maps and not seen the stairs down till i was watching the game, and not mini map. im wondering if you hit g in this situation if you would see the stairs down etc.
This actually looks small for a Catacombs map. Wondering if it’s a display bug with the map. I know in the beta, exits wouldn’t always show up… Perhaps one of the perimeter doors didn’t show up on your map?
Also, DarkSol… don’t forget that the Stony exit to DW isn’t always a cave entrance in the side of the mountain. It can be a cave in the middle of the map somewhere.
Ahhh yes. That may have been it. Been a number of years since I last got hooked on D2 
It can be a recent double map bug. Map can be showing walls from a previous game that are not there, and the exit is somewhere beyond them.
Stony Field can have cave-exit in a middle of the map as a hole. Just go on the road and you will find it.