here is my picture

Several other people have reported this, but I haven't seen a solution yet. Could you take a look through the discussion in these threads to see whether anything there helps or whether it suggests new avenues of exploration:

• Active Tab has floating chinese characters as well as the tab name how do I get rid of this?

• Asian words poping up on the Menu Bar and Tabs on Firefox Why?

Also, if you open a new window (Ctrl+n), does the same problem occur, or is it limited to the first window opened in a session?

I hadn't scrolled your screenshot over to the right, but I see some Chinese characters on your main toolbar. Do you know what is supposed to be in that area? You might be able to use the Customize feature to get more insight on that by moving that to the menu or off the toolbar.

General support article on the Customize feature: Customize Firefox controls, buttons and toolbars

nothing there. no customize feature

That looks to me like the separator or border between the star and the button to open the show your bookmarks popup menu.

Does it help to open a new window?

Are you using the default theme?

Can you post your extensions if you have any installed?

• https://support.mozilla.org/kb/Using+the+Troubleshooting+Information+page

I haven't tried open new window. Will try when it happens again. Yes I am using default theme.

for the 1st picture, when i move my mouse over the "star with weird character" it shrink back to normal and back to that again when i move my mouse away.

There are special ::before and ::after CSS rules applied to some elements.

• chrome://browser/skin/browser.css

I don't know how such code would be able to show UTF-16 characters.

happened again. i try new window. no weird characters

Do you use any "asian" program on your computer ? If you uninstall it, do you still have the problem on Firefox ? If not, I would rather think about a malware that came with another program you installed on your computer. Do you need help to try to clean your computer ?

No I don't have any asian program on my computer. I haven't installed anything lately except upgrade firefox to 34.0

https://productforums.google.com/forum/?_escaped_fragment_=topic/chrome/dwXd1qAy1v4#!topic/chrome/dwXd1qAy1v4

It seems that "changing the encoding from UTF to Western (Windows-1252) and everything should come back to normal".

In Firefox 34, F10 - View - Encoding.

I know that UTF should be a better option, but in this case, if it works ? (I checked on my Firefox, I'm under Western encoding)

Hi Gnarrrk, I'm not sure there is a convenient place to change the encoding used in Firefox's toolbar and tab bar area. Is this something you have experimented with?

It would be good if the font that is used to display the CJK characters could be disabled. Then Firefox would show boxes with the hex code that would allow to see what is means.

I tried to change from Uni - Western. weird character doesn't go away.

"View > Character Encoding" doesn't affect this issue as that setting only works for web pages and not for the user interface.

I uninstall and reinstall firefox. Let see if it goes away

edit: doesn't work. got weird character I ran malwarebytes and got nothing

Sometimes, MBAM is not enough. Look at https://support.mozilla.org/fr/questions/1034393#answer-660936 Cor-el gives a routine for security checking.

In addition, do you know Hijackthis ? It's a program that will find everything installed on your computer. donwload : http://www.filehippo.com/fr/download_hijackthis instructions : https://www.youtube.com/watch?v=FDWD9mhgeno

Hi, Jscher2000, I didn't experiment the "chinese characters" problem, but I've got some trouble with UTF characters diplaying, on Firefox. Well, using F10-View-Encoding works on my F34.0 : I can swap from western to unicode and back.

Cor-el : yep, that means the problem doesn't come from web pages or something displayed in the pages. It is why I believe that, in this situation, or Firefox, or your Windows, is/are infected.

Try to open a new window in case there is a problem with the current window.

hello xSanaNanax, some other affected users tied the issue to the mcafee site advisor extension - please try to disable or remove that in case you have it present.

Disable or remove Add-ons

You can try to disable the McAfee MSC FF plugin DLL plugin in "Firefox/Tools > Add-ons > Plugins"

If it is caused by a plugin then Safe Mode wouldn't have effect and thus wouldn't get noticed via troubleshooting extensions.

• https://support.mozilla.org/kb/Troubleshooting+plugins