I just upgraded my iphone to 11.0.3, and Mini updated to 16.0.4 (as reported in the app store) right after.
Mini crashed when I tried to open it. I got a white screen with the red O and the word Opera below it. Then it went away. If I double clicked to go to the app switcher, I got a ghost image of it open, but if I selected it it went poof, again with the white screen and stuff.
This persisted through a reboot, but a deletion and reinstallation cleared it up.
Annoying, but thought folks might want to know...
-jk