Some mods are kinda "dangerous" to use the word loosely.
Also I install my mods in groups of 1-3 at a time and load it up to check for possible conflicts.
When installing mods I must first check to see if the author has listed any known conflicts, then I read the bug reports for conflicts and issues as well as the comments for the same thing. I have so many mods that the game shouldn't work. I have also noticed that when my Graphics Drivers need an update the game crashes at start up, so I need to update them and restart my computer, this works 99% of the time for me, so long as I have the mods installed and loaded in the correct order. I had one time where it was so bad that I had to Uninstall everything, and delete all mods (with the exception of modernweapons as the creator took it off nexus). I suggest viewing the NMM Forums in regards to the matter.
I had and continue to have the same issue. It is crashing due to conflicts either between the mods, or how you loaded them.