Time: Monday, October 21st at 8:30 pm EDT
Frequency: Once.
World name: Sargatanas (Duty Finder)
Character name: Ceol Ashwin
NPC name: n/a
Monster name: n/a
Class/Level: PLD/50
Party or solo: Party.
In-game time: n/a
Area and coordinates: Castrum Meridianum
Steps:
1. Go into the instance with ~13% gear durability.
2. Fight enough enemies to get your gear to 10% and receive the notification.
3. Your gear will break completely before you make it to the last boss, making the notification worthless.

I'm sure quite a few people have had this happen. You spend all day grinding CM or WP or AK, and at the start of a run, you get this message:

The condition of your <gear> is now 10%.
The first time this happens, you figure, "Oh, I'll just repair when I leave!" Except 9 times out of 10, that last 10% isn't enough to get you the rest of the way through. Just now, I had to leave a CM instance because my sword and shield broke on the Magitek Colossus Rubricatus fight. The problem is, I got the 10% notification just after the first boss. If 10% isn't enough to clear a dungeon, there needs to be another alert at 20% or 30% so I don't stumble into an instance with gear that might as well be broken despite not getting any notification.