Latest daily build Win64
In the forest, at the screen with the log near the waterfall (room 81), clicking at the lower right corner (between the tree and the edge of the screen) triggers what appears to be a path finding bug.
Hero seems to understand that he has to go to the south screen, but can't do it directly at the requested coordinates.
So he walks/runs north a bit to the log, but then gets stuck instead of proceeding to the south screen. At this point, Hero stops responding to user input, you have to reload the game.
There is no warning or error msg.
It is impossible to replicate this under DOSBox. In Sierra SCI, Hero always goes right to the waterfall so never attempts to go south from there.
So that might be the root of the problem here.