Before I start, I will say that I have literally tried everything. Not average joe everything, I mean full on everything.
Windows 7, Firefox.
Last week, I decided it was time to reinstall my OS since I'd just bought some new HDDs and a new SSD. First thing I did was a full backup of my old, which worked without issue.
I then migrated all of my data over peice by peice, including both my Firefox profiles and the Macromedia folder in AppData/Roaming. I still have these backups.
However, when using twitch.tv and YouTube earlier, I noticed nothing was saving.. Twitch was defaulting to the lowest quality and max volume, and YT was defaulting to max volume. Naturally, I tried reinstalling Flash. No dice.
I then uninstalled flash, deleted both macromedia folders from AppData/Roaming and /Local, deleted all mozilla AppData folders, and then reinstalled flash and Firefox.
It still didn't work.
Since then, I've been trying every single combination possible. I have many, many years worth of flash game saves, flash config options, and various other things that I desprately want saved. My biggest issue here is the fact that even nuking everything didn't fix the issue. There was literally nothing left to remove, I even checked ProgramData. I've also checked permissions for any folders that I used to have in AppData, and it's all fine. Running everything in admin still doesn't make a lick of difference.
If anyone can help me with this, I will seriously appreciate it. This is getting me down now.
EDIT: Just thought I'd add that I've been through all the standard settings, and everything is set to be allowed to save.
EDIT2: Downgraded to 11.6.602.1 and everything works absolutely perfectly. This is ridiculous.