The UNDERDEEP solutions for the problems players actually hit are mostly about two things: the startup check, and the way the map behaves when a route is not set up properly. If the game will not launch it is almost always the network or clock check, and if a door keeps pushing you back the fix is a second marker on that tile.
The game will not start
The game checks the network and the system clock at startup and shuts down if the check fails. The recovery procedure for a launch that fails outright:
- Close the game.
- Press Win+R and enter %USERPROFILE%\AppData\LocalLow\Hakony\UNDERDEEP\
- Open the "Full" folder.
- Extract the "migrate_r" archive into it, overwriting the existing files.
- Launch the game again.
If the save is still missing, try "migrate_r1", which holds an older backup. Demo installs use the "Demo" folder instead of "Full", and the Linux save data directory is ~/.config/unity3d/Hakony/UNDERDEEP. Verifying the game's files through your launcher is the other standard first step, and the developer publishes support at cs@hakony.com.
Why the game refuses to launch in the first place is explained in the offline mode guide.
Underdeep solutions: the screen stays dark after fullscreen
Switch back to windowed mode, which clears it. Nothing else is needed.
A door pushes you back
A door that fails to unlock pushes you back one tile instead of letting you pass. Put two markers on that tile so the character tries again, and use the repeat key so the policy is re-armed every time the tile is re-entered. The marker rules are in the route settings guide.
Loot slots fill up during a run
The eight Loot slots fill up during a run and cannot be freed inside the dungeon. Duplicates are sold automatically when you return, so the run is not wasted, and items found during a run are worn from the character screen once you are back. What that means for the value of a slot is covered in the selling items guide.
The ticket window blocks the timer
When the loop tickets run out, the notice window blocks the free-cycle timer and has to be closed by hand. A missed click there costs the whole cycle - the ticket numbers are in the loop ticket guide.
Tiles you cannot reach
A dungeon can contain tiles that cannot be reached within your current vigor budget. The fix is coverage - raising the explored percentage, or taking the +10 vigor skill - not a bug report; players have been stuck in the third dungeon until they found the two missing tiles that opened the route. How coverage raises your reach is in the cartography guide.
Healing in the middle of a fight
Healing with a potion during a fight usually makes things worse, because the damage you take in the same turn can exceed the heal. Drink the potion between fights with the E marker on the tile you leave after the boss instead, which is covered in the potion healing guide.
The first dungeon's routes are short by design
The same 72-tile path can be repeated every run, so a slow patch is a route problem, not a save problem.