Today I solved at least 2 big problems that had existed for months. First, the game kept crashing when a level was reloaded. Second, occlusion culling was broken to the point of being unusable. Both of these issues were fixed when I updated Unity to a newer version, but not the newest version, which breaks the game. So I read through the past release notes to find a version that fixed bugs while not creating new ones. Most times big problems aren't solved so easily, but sometimes they are and those times are great.