Can't Right Click In Instances

It sounds as if this may be related to a User Interface issue, Alibs. I encourage you to follow the directions below:

Q u o t e:
1) *IMPORTANT* Exit the World of Warcraft to your desktop by logging out of the game and exiting. If World of Warcraft isn't closed, then these steps won't have the desired effect.
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, delete the "WTF," "Cache," and "Interface" folders.
4) Restart your computer.
5) Please do not reinstall Addons prior to testing the issue you were experiencing.
6) 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.
7) Upon launching the game, you should see the Intro cinematic movie and be prompted to agree to the Terms of Use. Once you authenticate past the login screen, the “AddOns” button should no longer be visible at the lower left corner of the character selection screen. Both points mentioned previously must hold true if you should complete the aforementioned steps correctly.

Please let us know if the issue persists after you have had an opportunity to try this.