There's currently an issue that can occur on the first click of a board, especially on the later stages. I've already investigated it and mitigated the problem in my local environment, and it should be fully resolved in the next update.
If it happened mid-game, it could be related to certain item interactions. I'm aware of a few combinations that can cause issues, but they're rare since it's quite difficult to obtain all the required items in a single session.
Appreciate the report, thank you :)