There apparently was a lot of clutter on the desktop, but it was mostly documents. (And based on operator skill level, that makes sense as grabbing video would be a couple of hoops too many to jump through.) Given that, the machine now has 120GB free space left so a lack of space seems unlikely to have been the cause.
It is bonkers that a cluttered desktop can stop unrelated applications from functioning properly (the mail database resides in another directory after all).
It is bonkers that a cluttered desktop can stop unrelated applications from functioning properly (the mail database resides in another directory after all).