Developed a 120 roll of TMY-2 last night with Ilford DDX. There was 100ml remaining in a bottle so I used it up. Mixed 4 to 1 as per instructions. Starting developer temp at 67 degrees, in a 68 degree water bath. Developer temp after process was just under 70. (Ambient 78) I usually see a 2 - 3 degree change in 8 min so I start a hair low.

Film came out totally blank - no edge lettering, no nothing.

Can't think of anything other than developer failure but I've never seen that in a couple of years of using DDX. Any thoughts???