Solved
Citadel: heating unit stabilizer
I know the game is a bit old and some guides don't clarify, but one says you must complete the heating unit stabilizer before priority: Tuchanka, do they mean priority 1 or 2 since there are two segments for it I'd really appreciate any help
If I recall this correctly you can only completed this mission after PriorityTuchanka.
You can not complete it before at all.
