It's look like problem with AppArmor rules. Just add this two lines to file /etc/apparmor.d/torbrowser.Browser.firefox (at line 6 or below):
# allow read glycin-loader for image loading I guess /usr/share/glycin-loaders/** r,# allow run bwrap. May be there are more suitable options than ux, I don't know
/usr/bin/bwrap ux,
