Just wondering whether anyone else has encountered this issue: My last two villages were doing pretty well (I failed on day 14 in the most recent game, but made it to day 18 in the one before that), when my maze/tower defense system was suddenly undermined by a tree randomly appearing in the middle of my wall maze (bottom right in the linked picture).
My city was on the left side, and it had a line of towers along the inner side of the wall. The monsters would file into the entrance at the top right, where they would get mowed down before they could make it all the way to the exit at the top left (the openings for the entrance and exit were intentionally left open so mobs would walk an extended path length while under fire, instead of just tearing down the wall in a random place). In both cases, this was going fine until a tree (which the AI treats as a wall) appeared at the bottom of my maze, forcing the monsters to create a new opening (which they did at the red line). With a direct path into the village, my defense towers and all other buildings were gone almost instantly.
Is this a bug? On the one hand, I guess it makes sense that trees might grow sometimes—but on the other hand, it seems impossible to last even one full year without a reliable maze/tower defense system, which in turn seems impossible if the maze can be blocked off without any warning or notification. Assuming it's intended behavior and not a glitch, does anyone have workaround ideas (that don't involve a double-wide path)?