The first step in finding a problem mod, should be to disable the first half of your listed mods. If this fixes the problem, then you know the issue is in the second half. If not, then the problem is in the first half. In essence, it doesn't matter if this first step fixes the problem, because either result will tell you which half to continue testing. From here on, continue cutting your load order in half, until you've found the problematic mod. This effectively allows you to test 64 mods in six checks, 128 mods in seven checks, and 256 mods in a measly eight checks.

That's much faster than enabling and disabling mods individually. You can extend this to conflict issues with, say, open cities, by simply leaving that one enabled throughout the testing process. You'll home in on the mod that's conflicting with open cities in a rather small number of checks. You can extend this to work with any mod or DLC, so it's pretty versatile.

The next time someone posts a thread about 'finding a problem mod' in their load order, just point them here.