I have no idea why you would need to verify NVSE or JIP... Never have nor have heard of anybody doing that.
But as for drag and dropping, is your FNV folder set to "read only" possibly?
There might be a solution here too:
https://support.microsoft.com/en-us/help/2623670/access-denied-or-other-errors-when-you-access-or-work-with-files-and-f
_________________
____________________________________________________________
When you're lost in the darkness... Look for light