I think you did this already but I will put it in here anyway.
Open your minetest.conf file in a text editor. Add this line
Your phone or window isn't wide enough to display the code box. If it's a phone, try rotating it to landscape mode.
Another option is to start up the game and in chat type
Your phone or window isn't wide enough to display the code box. If it's a phone, try rotating it to landscape mode.
This might take a little time depending on the size of your map.
If this is an issue with someone that travelled outside the map then do you know who it was?
If so then open /minetest/worlds/Your_world/players/Player_Who_did_it in a text editor.
Change their position to a position inside the map and save.
Restart the world and see if that worked.
You may have to look through all player files to see which it is.
you can use grep to search all the files.
These are thoughts off the top of my head. They might help and if not then someone will find a better answer.
Hope this was clear enough. If not then ask me for clearer instructions.