We are deep into wedding season, and just today, when I was starting to edit photos I noticed that the lens profile for my Canon 35mm f/1.4 USM lens is missing. It seems that all the other canon profiles are in tact - and this profile has been present for the last year and a half since I bought the lens.
I can't find a clear cut way to get this profile back. I tried installing a past version of LR to see if that would work, but it did nothing.
Can someone please help me?
I don't suppose there's any chance you're trying to edit a non-raw image, right?
Yes, that is the most likely explanation. Lens profiles don't go missing all by themselves, and Adobe has no reason to remove old lens profiles on an update either. So if people say that a lens profile is missing, they almost always have selected a non-RAW image (jpeg, tiff). Most lens profiles are for raw only, so they won't show when you've selected a jpeg. What happens quite often is that camera settings have changed from raw to jpeg without the photographer even realising it. For example because you brought the camera to a sensor cleaning service, where they changed it to jpeg so they could quickly check their results. The Reikan Focal software for AF-calibration also changes camera settings to jpeg.