The shredder for the quest Eye for an Eye dies too quickly.

What to do if you can't complete this quest.

Information on stuck Dragon's Eye Gems in Gloves or Bracers after abandoning Blacksmithing in Wrath of Lich King Classic

Troubleshooting this Bloodsail Buccaneers quest

What to do if you get an error that says you cannot carry more of those.

Troubleshooting issues with turning in this quest

What to do if you have not completed the "His Eye Upon You" quest that cleanses this buff but it is missing. 

What to do if you can't loot Eternal Embers after defeating Ragnaros in The Firelands in Cataclysm Classic.

What to do if the spell is greyed out or you receive an error "You can't do that yet"

What to do if you can't start or complete the Legion Introduction