I ran into a similar problem a week ago. When you add a package using mrt
it automatically updates all of your other packages (good feature?). So when you added bootboxjs, it updated your bootstrap3-less package to use their new naming scheme, which is *.import.less
rather than *.lessimport
.
In order to fix this you have to update your references to any bootstrap related less files to *.import.less
.
I would recommend just going back through your bootstrap configuration and making sure everything is as it should be according to their new docs.