Map generation bug

My map is unbeatable because terrain generation created a wall in the middle of the path along its entire length, making it impossible to pass.
I can see the enemies on the other side and kill a few through a window in the wall texture. I ventured back to check if I had missed a path, but I can clearly see the edge of the entire map, which I was able to clear.

In the end I died trying to take screenshots, killed by the mobs on the oter side of the wall so mobs can allso target me through the window.