i think this will help

go to ur wow folder (etc: C:\Program Files\World of Warcraft)
There should be few folders there, look up for WTF, Cache and Interface. Rename all 3 with extra "-OLD" on it. (etc: "WTF-Old," "Cache-Old," and "Interface-Old."
Restart ur pc after tat... and turn on WoW normally again...

WoW gm thought me this way whenever something is wrong with ur WoW. It works more like a reset button for ur wow, except u dont need to reinstall everything

this is the real mail that gm send to me

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Thank you for contacting the World of Warcraft Game Master Department.

After some research it appears the issue you are having may be related
to your User Interface (UI). This applies whether you have a custom UI
or not. To help resolve this issue we recommend the following steps:

1) Exit the World of Warcraft to your desktop by logging out of the
game and exiting.

2) If you used an "installer" for a custom UI, see if it has an
"uninstaller" and use it.

3) Inside the World of Warcraft Program Folder, rename the "WTF,"
"Cache," and "Interface" folders to "WTF-Old," "Cache-Old," and
"Interface-Old."

4) Restart your computer.

5) Make sure that you are using WOW.EXE or LAUNCHER.EXE to start the
game. Please do not run any UI installers beforehand, as we want to
eliminate them as part of the issue.

If these steps do not resolve your issue, please submit a new In-Game
ticket and we will attempt to assist you further.

Thank you again for contacting us. We hope you continue to enjoy your
experience in World of Warcraft!

*** Please do not respond to this email as all conversations on this
matter would be best handled online. **
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