Strange Mysteries has a 14-mnute short film “5 Things that Will Happen When Aliens Arrive”.
This isn’t one of those cheesy web sites that make you load a new page and ad to see the next “thing”.
Stephen Hawking is mentioned. The upshot is that an advanced alien civilization might make a brief, non-aggressive visit, depart, and leave us alone.
Hawking's own views are much more guarded. European conquests of the New World did not work out well for native populations.
One obvious problem could be the introduction of alien pathogens.
The conclusion of my screenplay script “Titanium” poses such a situation, as would the sequence “Prescience”.