Scenario: If you saved a game with the tree limit set to one million, the forest brush will use the buffer index provided in existing buffer to save precision information.
If you then shrink the buffer to 7 hundred thousand tree limit, my mod will repack as many of the trees into the existing buffer. This repacked buffer will cause Forest brush to cause array index out of range exception error.

The game should still load fine, and no noticeable problems would occur. Saving the game might re-index the Forest Brush precision data.

Solution: There's no solution for this as trees are randomly packed when tree limit is shrunk, thus make sure to keep using the same tree limit in a game save, and don't shrink it. Then everything should be fine. You can expand the limit to support more trees without issues.