P: DNG file is damaged yet it can be processed in other applications

[marchyman]

Issue:

Lightroom claims a DNG file is damaged yet it can be processed in other applications.

Provide Lightroom Classic version:
11.3 Release Camera Raw 14.3
Build [202204051513-7a25c809]

Provide OS and version:
macOS Monterey
Version 12.3.1
iMac (Retina 5K, 27-inch, 2019)
Processor 3.6 GHz 8-Core Intel Core i9
Memory 64 GB 2667 MHz DDR4
Startup Disk Macintosh HD
Graphics Radeon Pro 575X 4 GB

Issue:
When attempting to edit a handful of DNG images in my library Lightroom claims:
"The file appears to be unsupported or damaged."
That message appears in a popover on an imbedded preview.

Of interest:

• Mac finder can process the image.
• Mac Preview.app can process the image.
• Affinity Photo can process the image.
• Exiftool can read the image metadata

My workaround is to convert the image to another format using Finder or Preview or Affinity Photo.

Also of interest: Every damaged DNG was created by a Leica  camera and subsequently modified by an older version of Lightroom Classic, specifically Adobe Photoshop Lightroom Classic 9.0 (Macintosh).  Exif data says:
   History Action : saved

   History Instance ID : xmp.iid:375df6ee-7fb1-479c-8be6-e122486b8583
   History When : 2019:11:30 22:16:20-08:00
   History Software Agent : Adobe Photoshop Lightroom Classic 9.0 (Macintosh)
   History Changed : /metadata

I can not reproduce damaged files upon demand.  I uploaded an example of a damaged image.  Out of approximately 6,000 DMG images in my library less than 20 are damaged. 

Expected result:
Lightroom Classic should be able to edit the image.  At a minimum I should be given the option to attempt to render the image regardless of the report of damage.

Actual result:
Lightroom Classic can not edit the image. I must first convert the image to a different format using some other application

[TheDigitalDog]

Can you re-convert them to DNG either using LR (again) or the DNG converter? 

Can you open the 'damaged' DNG in Camera Raw? 

That the DNG was directly from a camera, I have to wonder if that camera isn't following the DNG spec's properly or if it is using a very old version of DNG. In the DNG converter, the most up to date version of the spec is V14, hence converting these using this utility and that setting might be worth looking into. 

[marchyman]

Can not re-convert using LrC.  DNG  converter fails, too -- "There was an error parsing the file". 

Didn't try ACR (don't have Ps on this system) but I suspect it will be the same.

Did you miss the part where I mentioned that all of the bad DNG files were not directly from the camere, but last updated use the Save (cmd-S) option in LrC version 9?  I suspect whatever it is that LrC doesn't like today was caused by saving metadata changes using LrC in 2019.  Don't know if the error occurred then or of today's LrC is being overly picky.  I suspect both... LrC 9 did something wrong and the current LrC et al are being extra picky.  exiftool gives a minor warning for the bad files:

Warning                         : [minor] Bad offset for MakerNotes tag 0x0301

Warning                         : [minor] Error reading value for MakerNotes entry 2

but I don't know that such minor errors are what is causing LrC to not process the files.  Good thing I can convert the files to jpg, heic, tif, etc., using non Adobe apps.

[TheDigitalDog]

Not good news; seems these DNGs may really are corrupted based on your reporting. But you can edit, then render (export) JPEGs or TIFFs? 

Hopefully, you have backups and you really want to check out that your drive isn't wonky and causing this. 

[marchyman]

Yes, I can render using non-Adobe products.

It’s only a handful of images.  It just annoys me that I can edit them in Preview (after converting to tif) or in Affinity Photo but not LrC. Instead I convert them to heic using Finder, sync the folder containing the bad DNG and the converted image, then group the heic along with the bad DNG in LrC.  Then I can use LrC to edit the heic version should I desire.

[dj_paige]

Sometimes when a RAW or DNG image is damaged, other applications can show the image properly because these other applications are working from the embedded JPG preview in the file (in other words, they are not showing you the RAW or DNG version of the image). It does happen that the RAW or DNG image is corrupted/damaged but the JPG preview is not damaged. So my conclusion is that these are indeed corrupted images, that Lightroom Classic and the DNG converter are giving the correct answer.

[marchyman]

Perhaps that happens but that does not seem to be the case here.  LrC is showing me the preview.  It tells me that.   It wasn't until I tried to render standard previews for the images in question that LrC told me the DNG was damaged.  The quality of the LrC shown previer MUCH lower than the quality of the images shown by 3rd party apps.

Exiftool tells me how large a preview is.  Here is one example

Preview Image                   : (Binary data 5673 bytes, use -b option to extract)

That preview image is a very small 160x120 pixels.  The converted image is a 5976x3992 pixels in size.

[TheDigitalDog]

So if you can actually render the "damaged' DNG to a full-sized TIFF or similar using LR, you're probably fine and for whatever reason, this report of damage is wrong. 

Maybe time to reset LR prefs? 

[dj_paige]

Perhaps that happens but that does not seem to be the case here.  LrC is showing me the preview.  It tells me that.   It wasn't until I tried to render standard previews for the images in question that LrC told me the DNG was damaged. 

This is exactly what I said. JPG preview is un-damaged, DNG is damaged, this happening in the same file. I don't see why you say "that does not seem to be the case here".

[marchyman]

I don't think the message is wrong, I think that Adobe is being overly picky.   The DNG isn't perfect.   Exiftool tells me there is a minor warning.  My guess is that Adobe sees that and refuses to process the image.

[marchyman]

The preview is 160x120 pixels.  The rendered imagee is 5976x3992 pixels.  No software can create a good quality 5976x3992 pixel image from a 160x120 sized preview.  It is my belief that the non-Adobe software is indeed rendering the raw data.

[TheDigitalDog]

Again, IF Adobe can render that DNG to it's full resolution which sounds like 5976x3992 pixels, then I'd agree, the message is overly picky. If Adobe can't, then that's another story. 

[andreas24134253ee9o]

After changing to new Ps and LrC I can´t open some of my DNGs created with one particular camera, others from same camera, from same series work well. The files are declared damaged by both programms but can be easyly be opened with Preview on Mac.

[dj_paige]

Many of the non-Adobe programs show you the JPG preview that is embedded in the DNG file. Many times, the JPG preview is undamaged while the DNG is damaged. 

So, almost certainly the DNG is damaged and Lightroom Classic can't use it. You can try transferring the DNG file to your computer from the camera again, to see if that clears up the problem. Also, you can try this transfer with different hardware to see if that makes a difference.

[johnrellis]

"one particular camera"

What's the exact make and model? There have been a few other reports here of similar symptoms.

[andreas24134253ee9o]

It´s a Leica M Type 240 the DNGs come from. The embaded RAW Converter should handle DNGs from this model. Affinity Photo opens the RAW file while Ps can´t handle it at all.

[andreas24134253ee9o]

It´s a Leica M Type 240 the DNGs come from. The embaded RAW Converter should handle DNGs from this model. Affinity Photo opens the RAW file while Ps can´t handle it at all.

[johnrellis]

Here's another report of Leica DNGs with similar problems:

https://community.adobe.com/t5/lightroom-classic-discussions/some-dng-files-are-nt-compatible-anymor...

This might have something to do with Leica-generated DNGs. On the other hand, it could be the issue has nothing to do with Leicas per se, but rather that a disproportionate percentage of DNGs cataloged in LR come from Leicas, one of the few cameras to generate DNGs natively. So if someone experiences hardware failure causing DNG file corruption, there's a higher-than-average probability the camera is a Leica.

[johnrellis]

Here's another report of Leica DNGs with similar problems:

https://community.adobe.com/t5/lightroom-classic-discussions/some-dng-files-are-nt-compatible-anymor...

This might have something to do with Leica-generated DNGs. On the other hand, it could be the issue has nothing to do with Leicas per se, but rather that a disproportionate percentage of DNGs cataloged in LR come from Leicas, one of the few cameras to generate DNGs natively. So if someone experiences hardware failure causing DNG file corruption, there's a higher-than-average probability the camera is a Leica.

[marchyman]

Yes.   But...  there's always a but, isn't there 🙂  I have about 6,500 Leica DNG files in my catalog.  Only a handful of them, less than 20, are being reported as damaged.  All of the damaged images were updated by LrC 9.  That could, of course, be pure coincidence.  Also, the Leica generated DNG could have had something incorrect which didn't cause issues until the file was updated by LrC 9.

LrC 9 had no problem opening the files.  LrC 9 had no problem saving metadata to the files.  LrC 11.3 reports the files are damaged.  This leads me to believe either the files were damaged (written incorrectly) by LrC 9 or the files were damaged in some unknown way sometime after LrC 9 updated the DNGs.  In either case Adobe products are giving up on processing the image where at least some other software has no issue.

[garryfuller]

Hi, I am having similar problems, Leica 240 and the most recent version of LR.  

Shooting RAW & jpeg, most of the images imported correctly but 2 or 3 DNGs are unable to be imported by LR via the same error message above.  I converted the affected DNGs into jpegs using MacOs Preview

Also exporting a number of images for archive (exporting from LR as hi-res jpegs) and DNG files correctly imported a month or two go (and edited in LR) are now reporting the same error message.

It very much feels like random DNGs, on both import and export, are 'falling over' for some reason.

[dj_paige]

Hardware malfunction (specifically the hard disk) is the most likely culprit. Run diagnostics on your hard disk.

Restore the photos from their backups.

[garryfuller]

Diagnostics run on the USB key and no issues.  Not tried backup files yet but will do

[dj_paige]

I said: run diagnostics on your hard disk.

[andreas24134253ee9o]

I´ve tried that allready with same result. 

[garryfuller]

Thank you for the reply, my 'working photos' are kept on a USB key but I have done as sugested and also run a diag on my Macbook hard drive, all is ok, no issues found.

I shoot DNG compressed, maybe that is it?  I'e switched compression off and will try a few shots this evening.  Thanks again for your time tryingh to help.