Anonymous
When you install apparmor, its installation sets a default policy configuration (application profiles).
You may not (probably will not) wish keep all of the as-shipped settings.
http://wiki.debian.org/AppArmor/HowToUse
I haven’t often used apparmor, so cannot offer further coaching on this.
“this is education”
AppArmor administration is not trivial. For example:
http://www.lynda.com/Linux-tutorials/AppArmor/618702/802563-4.html
^— this is described as a 12hour long course.
apparmor… firejail… virtualbox
Virtualbox running under firejail? Nope, I have never tried that & can’t guess whatall might go awry in that scenario. When mix-n-matching redundant layers of isolation, it’s important to keep careful notes describing steps taken. If you have not kept adequate notes (which seems to be the case), my “compassionate” recommendation now is: abandon the wrecked system, reinstall.