Refer to these forum threads in relation to the same issue.
Have you tried going all the way back to the initial entry/exit point of the game scene/mine where it says "do you want to leave this location"?
Do not stand right on the entry/exit point itself....just stand near it & try activating the Last Tile Finder from there.
Also have you tried clearing your cache, cookies, history, etc?
Have you tried fully shutting/closing down & re-opening your game?
If none of these suggestions work for you....then I recommend that you contact Pixel support directly.
You can contact Pixel support directly via your game settings menu.
Check your email spam/junk email folder for replies.
Don't send multiple tickets in quick succession to Pixel support otherwise their email spambot might eat them.