I have been enjoying this game a lot but have encountered this bug a few times now. Fortunately it is an easy one to avoid.

If you 'lock' a die onto one of your adventurers after failing the first rolls and then do so again with a different character at the same location (such that you now have two locked dice on two different adventurers), you lose the ability to "toss a die to the void" to allow for another set of rolls. Since you cannot re-roll and there is no option to fail the adventure, there is no way to proceed and you must restart the game.

To clarify, I am referring to when one is "focusing" and "assisting", with two different adventurers. If the last two dice are the two "locked" dice, gained from focus and assist, there is no way to complete or fail the task in order to continue the game.

Sorry, difficult to describe, hope that makes sense.

you can always fail the adventure by clicking the adventure title and choosing that option. I n my experience though clicking the 'book' when in that situation automatically fails and return you to the map.