Inconsistent RAW rendering (+18 EV exposure / white images) across machines on same NEF + XMP

Is there an existing issue for this?

• I checked and did not find my issue in the already reported ones

Describe the bug

I am experiencing inconsistent RAW rendering behavior in Darktable across multiple machines using the same version, the same NEF files, and the same XMP sidecar files.

Environment:

• Same Darktable version on all machines
• Same NEF files (Nikon RAW)
• Same XMP sidecar files
• No manual edits applied differently between machines

Problem:
On different machines, the same images are not rendered consistently in darkroom.

Symptoms include:

• Exposure module sometimes automatically set to extreme values (e.g. +18 EV)
• Images appearing completely white in darkroom
• After resetting exposure and demosaicing, the image may render correctly again

Important observation:
Across 3 different machines, the issue does NOT affect the same images consistently.
An image may render correctly on one machine but be broken (black/white or extreme exposure) on another, even with identical files and XMP.

Steps tried:

• Removing XMP → issue disappears but i loose modifications
• Resetting all modules → issue disappears but i loose modifications
• Resetting exposure and demosaicing → sometimes fixes rendering
• Copying full user configuration between machines → no change

Actual behavior:
Non-deterministic RAW rendering depending on machine, including:

• extreme exposure values (+18 EV)
• white images
• inconsistent behavior per machine (same image may or may not be affected depending on the machine)

Additional notes:
When importing only the problematic images, Darktable sometimes displays error/warning messages in the UI.

Steps to reproduce

1. Open Darktable on Machine A and Machine B (same version installed on both machines).

2. Import the same Nikon NEF RAW and XMP files into both machines.

3. Open the image in darkroom on both machines.

4. Observe that the rendering differs between machines, but only for certain images:

   • The issue does NOT affect all images consistently.
   • Some images render correctly on all machines.
   • Other images render differently depending on the machine.

5. For affected images:

   • On one machine, the image appears correctly exposed.
   • On another machine, the same image may appear completely black or white.
   • Exposure module may show extreme values (e.g. +18 EV) on one machine.

6. On the affected machine, manually reset exposure and demosaicing modules.

7. Observe that the image may then render correctly again.

Expected behavior

Expected behavior: Consistent RAW rendering across machines with identical files, XMP, and software version.

Logfile | Screenshot | Screencast

I ran Darktable with full debug logging and attempted to open one of the problematic images (DSC_5520.NEF).

Command used:
darktable -d all

The corresponding log file is attached below.

darktable-log.txt

Commit

No response

Where did you obtain darktable from?

darktable.org / GitHub release

darktable version

5.4.1

What OS are you using?

Windows

What is the version of your OS?

Windows 11

Describe your system

No response

Are you using OpenCL GPU in darktable?

I dont know

If yes, what is the GPU card and driver?

No response

Please provide additional context if applicable. You can attach files too, but might need to rename to .txt or .zip

No response

Start by reviewing the attached darktable-log.txt from opening DSC_5520.NEF with darktable -d all, then compare the same NEF and XMP on the affected Windows 11 machines. Check the exposure and demosaicing state, import warnings, and whether OpenCL differs between machines; done means identifying a reproducible cause or the missing diagnostic information needed to explain the inconsistent rendering.