I have googled and read several posts on this, but I am still having a hard time coming to grips with this loss. I need some advice and suggestions on how to track down what could have gone wrong. I shot a roll of 120, Agfa APX 100 (fairly old, like 10 years) in my Mamiya 645 Pro TL. Souped it in Rodinal 1:50 for 13 minutes. The negatives came out bleach blank, absolutely no trace of black. except of course the edge markings which are clearly visible. I was extra careful as always in checking the order of developer, stop and fix going into the can, therefore the fix before developer is ruled out. When I poured out the can after developer, the liquid was dark purple! I checked the camera and shutter and nothing seems to be wrong that can cause major light leaks. The film was loaded correctly and I checked it when I took the exposed roll out of the film back. I loaded the film into reels inside a bag with lot of care as always. Could it be a fogged film? It took it out of a wrapper when I loaded it. I am tempted to go try out the same film, camera and souping combo once again and see what happens. But I thought I would post this question to seek some help to narrow down some scenarios that could have caused this. Good thing that there was nothing valuable in the shots. However, I must admit that it is really heartbreaking to pull out blank negatives after all the effort in shooting and then going through all the inversions and swirling with high expectations at the end.