[FullRangeMan]

The Chinese characters are part of a favorite, they appear on the monitor 1 when I see videos on the monitor 2.

Any solution?

[jmc207]

The McAfee SiteAdvisor extension has been reported to cause this. Disable it and see if that helps.

https://support.mozilla.org/en-US/questions/1034692
https://support.mozilla.org/en-US/questions/1035523

[srb]

If it turns out not to be the McAfee Site Advisor extension, you can often troubleshoot problems like this by restarting Firefox in Safe Mode.

Help > Restart with Add-ons Disabled

Firefox will close and present a dialog box - Select Restart in Safe Mode (Do not select Reset Firefox).

If you're able to view normally there is likely a problem with another Add-on Theme or Extension.  You can then disable Add-ons one by one and perhaps find the culprit.

Your screen resolution is likely wider than many other users (> than 1366) and requires scrolling.  Consider uploading smaller width photos if the additional width adds no usable information.

Steve

[FullRangeMan]

Prob solved! Thanks guys you are the best.

[FullRangeMan]

The problem kept happening sporadically.
Then one day I noticed there was a huge amount of .db files scattered in folders, including in the work area.
The files were thumbs.db and other similar names, after a long manual inspection in all folders FF cameback to normal.
So some months after at end of a google work, I saw the Mr.G in action doing sabotage in FF at my PC.
The .db files were illegally installed on my PC by Google.
The files contain programing, tags and a long plethora of FF favorites details.