[tor-talk] Tor Browser Security Settings warning

[Joe]

Probably around the time of recent changes in Tor Browser / TorButton, I 
started seeing a warning when I click on Security Settings in Tor Button.

Pop up title: Tor Browser Security Settings
Security Level
"Your custom browser preferences have resulted in unusual security 
settings.  For security and privacy reasons, we recommend you choose one 
of the default security levels."

After that, only a "Restore Defaults" button shows in the message - no 
options to choose from.  That's part of the problem.  If I try to check 
TBB's security level setting (low, medium, high) it always shows the 
message above.
I can click Restore Defaults, but next session - w/o me changing 
anything in between, it shows the same message if I try to check 
"Security Settings."

As far as I've ever been able to tell, clicking Restore Defaults doesn't 
change anything under the browser Preferences > Privacy tab or anything 
in NoScript.

In TBB - Preferences > Privacy, the only non-default setting I know is 
"Remember my browsing & download history" is checked.
But all data is set to be deleted when browser closes.  TBB does that 
anyway.
All other settings in Preferences/Privacy are default.

After several times (sessions), over the last few TBB versions, of 
clicking "Restore Defaults" (security settings) the next session it 
shows the same popup if I check security settings again.

Other than that, I don't know what "unusual settings" it means, or if 
Tor Button security is slightly broken?
The security slider is usually set on low; sometimes medium.  That 
doesn't affect seeing the popup.