If you find that the film is completely blank after developing, it’s usually 99.9% your fault. Behind that 0.1% could be a camera shutter defect. But it always means that what you photographed will remain only in your memories. Sometimes it happens that you first pour the fixer into the developer tank (happened to me once so far). As soon as I saw that the film was empty, I thought I had poured fixer instead of developer. This would mean that I then poured the contents of the developer into the wrong containers. So I disposed of the developer and the fixer. Since I still had a few undeveloped negatives, I mixed the developers and fixer again. I just resealed the camera due to light leakage. So at that point I had no idea if I had sealed the camera well. Immediately after I mixed the new solutions, I noticed that the length of film illuminated corresponded to the length of film that had not yet been loaded in the camera. In the amount of negatives, I simply inserted the unexposed film in the developer tank. So, thanks to my own mistake, I only lost one film and two liters of chemistry. But no photo… luckily. The film I wanted to develop was still in the camera. When I finally developed him up, I was sure the seal repair had gone well. Nevertheless, I dried the empty film and kept it for teaching to those interested in the analog process🙂🙃📷