There have been other rare reports of the Spot Removal Brush not working on images.
I experienced it once, with only one photo, I could not heal or clone one small area on the image- the rest of the image would heal ok!.
I have not seen an answer to this rare issue.
It might be a glitch in the graphics card, or Lr does not update the image preview.
Most obvious answer is to check the 'Feather' and 'opacity' slider settings, but my issue occurred with Opacity=100 and Feather~80.
Also try making a copy of the image file in File Explorer, import, and try the Spot Brush on this image.
It might be worth updating the Graphic drivers also.
Hopefully an answer might come.
Sadly, I tried both making and editing a copy of the photo, and updating my graphic driver, but neither solved the problem. I guess I will have to edit these flaws in Photoshop, despite the inconvenience of going back and forth, and removing and re-importing the files. My experience is like yours: other spots in the images will heal and clone fine, but not these odd-ball ones. And that's with Opacity=100 and any amount of Feathering.
I'm wondering if there is something unusual with these flaws. They do look different onscreen than typical dust spots. I read something about Clone/Heal not working on areas with no color, like those outside of an image. I'm working with scanned images and maybe the area of the photo is actually missing emulsion, so when scanned there are no pixels for LR to work with? Although there should still be digital color there, just of the picture backing. So who knows?
I don't suppose there is any chance Adobe will fix it. It's not especially rare for me as I'm finding the problem in about 1 in 20 or so photos. Oh well. In any case, thank you wobertc for your suggestions.
It would be interesting to see a screenshot of the problem, and maybe you could make one original available for us to download on Dropbox?
We can only test the clone brush on an original image file. Can you copy the whole file to Dropbox?
The (screen-clip) jpgs you posted show the problem but don't allow us to test the image in our Lightroom.
Are you scanning as JPG, PNG or TIFF?
My experience was not 'transparent pixels'. I was trying to clone away a flower that was in the wrong location, and the Spot Healing brush would not touch it whatsoever.
OMG I figured out what it is--you are going to laugh. I've been using the Paste Settings from Previous to make it easier to adjust multiple similar photos. The 'flaw' is the teeth whitening from the previous photo!! No wonder it looked oddly familiar.
Now why it is doing this I have no idea. I've uploaded 2 more files: a screenshot of the Copy Settings dialog box, and a photo showing the pasted whitened teeth. I had assumed that the Paste Settings from Previous was limiting itself to selections in the Copy Settings dialog box, but clearly it isn't.
I guess there isn't any way to limit what it does and doesn't paste. I could use the Copy Settings and Paste Settings instead, though it does add a few extra steps to the workflow. Or, I could keep using Paste Settings from Previous and then use the Adjustment Brush to reset or delete the teeth (or any other adjustments) from the new photo. How annoying!
I'll be interested to hear if the flaws you are encountering are a similar artifact pasted from another photo's corrections. If they are, you should be able to use the originating tool to delete them.
Thanks very much!
I'm not laughing because that's happened to me a few times. Yes, Paste Settings from Previous doesn't depend on the Paste Settings dialog box, you always get everything. If I'm using Paste Settings from Previous taken from an image that has local corrections I know I don't want, I try to remember to click Reset for each of the local adjustments before applying them to a third image.
For example, I'll use Paste Settings from Previous on an image, then press M (Graduated Filter) and click Reset, press Shift-M (Radial Filter) and click Reset, press K (Adjustment Brush) and click Reset, press Q (Spot Healing) and click Reset. Only then will I go to the next image and use Paste Settings from Previous again.
I don't know if anyone has submitted a feature request for a way to have Paste Settings from Previous ignore local adjustments or respect the Paste Settings selections, but it would save a lot of work.
It certainly would! I was so surprised that it didn't accept the settings in the Copy Settings dialog. I had spent time editing them for just that reason, which is why I didn't realize what was happening.
And I just realized I didn't post links to the new files I uploaded so there they are if anyone is interested: