Bug#851066: Forget it and move on
Since flash will deprecated[0] in 2020, I doubt this bug will be fixed somehow. So as a reminder of old news, please purge it and move on. https://blogs.adobe.com/conversations/2017/07/adobe-flash-update.html
Bug#864924: virtualbox GUI not more working
Strange, my VirtualBox GUI is still working. pdofn14@ASMDT-TN14:~$ LANG=C virtualbox Qt WARNING: libpng warning: iCCP: known incorrect sRGB profile pdofn14@ASMDT-TN14:~$ It's only about useless warning.