I have been processing C41 film at home using the Photographer's Formulary Kodak Flexicolor kit. Occasionally, my negatives show vertical pink bands on an edge of the film when scanned. In the example below the condition can be seen on the left vertical edge of the image and is most easily seen against the blue sky.
Does anyone know what is causing this to occur? Thanks for your help!
The Hospital by Thomas N. Abbott, on Flickr