First, if you have not, go to github and download the alternative mod launcher. It at least completely sees mods and completely loads mods. The launcher now is anyone;s guess how well it sees and launches mods. That takes care of error possibility #1.

Next, go to documents, find the game folder, dig in to find the config folder, delete the configs and rebuild them if you have not recently. They degrade on their own and adding more or removing more or even lots of mods used the faster they degrade to give some fatal or strange errors.

Last, using AML, load by halves. Those no error, add half of the remaining. Still no error, again, half of the remaining. Once you have the error, same thing with that group, add them again by halves narrowing the error down.

EDIT: AML also detects conflicts which are obvious and allows you to choose file priority. As well, once mods have been cleared, you can add them to a name group so you know they have been cleared.

thanks for the advice, I'll give it a try