That's really weird and never happened before in any playtest :/
The coins are not related to the solution! Can you tell me which version you played? (Language/OS) Thanks! And let me know if the bug goes away when you play another time. Sorry!
Alright. Yeah that is one of the ways I tried to solve it.
I was playing the v1.5/English/Windows version.
When playing it a second time using the same route, it still seems like I get in the same state after completing the puzzle.
The state the game gets in is: All that I can do is continue modifying the puzzle, click the X to exit the puzzle screen, continue collecting coins, and/or hire workers.