Issue: Browsing JPG photos in XnView MP has suddenly become very slow

[Commodoortje]

Issue: Browsing JPG photos in XnView MP has suddenly become very slow.

Loading the next photo takes about 3–4 seconds per image.
The photos are stored on a Synology DS723+ NAS (20 GB RAM).
Other applications (IrfanView, Windows Photos, Synology Photos) browse the same files without any delay.
The problem does not occur when the photos are copied to my local SSD (Windows 11 system drive).
The issue appeared suddenly from one day to the next, without any obvious change in my workflow.
I have tried several settings and troubleshooting steps, but so far I have not found a solution.

Has anyone experienced a similar issue or found a fix?

Version XnView MP 1.11.2 [10051] 64-bit (Apr 300 2026 - Libformat 7.239 (Windows)

[xnview]

Browsing photos in an image tab? Which format?
It was the same version when fast?

[Commodoortje]

I have managed to solve the issue where opening JPEG files became extremely slow (about 4 seconds per image). Unfortunately, I no longer know exactly which setting solved it, because I changed several options related to image rotation and EXIF orientation while troubleshooting.

However, after fixing the performance problem, I now have a new issue.

All my JPEG images are displayed rotated by 90° in XnView MP. They are displayed correctly in Windows Explorer, Windows Photos, and other image viewers, so the problem seems to be limited to XnView MP.

The EXIF Orientation tag of the images is "Right-top (6)".

I suspect that during my earlier attempts to fix the slow loading problem, I accidentally changed a rotation or EXIF-related setting in XnView MP. It is also possible that I performed a batch rotation incorrectly.

Is there a way to restore the correct orientation in XnView MP without having to rotate all my images again? Or is there a setting that controls how XnView MP interprets the EXIF Orientation tag?

Any suggestions would be greatly appreciated.

[Commodoortje]

I uninstalled and reinstalled XnView MP.
This resolved the issue where all images were displayed rotated by 90° in XnView.

[jkm]

Welcome to the forums...

I uninstalled and reinstalled XnView MP.
This resolved the issue where all images were displayed rotated by 90° in XnView.

Right, so then you either had incorrect settings (which was fixed when the ini file was rebuilt) or incorrect cached thumbnails or metadata, which was fixed when the database was rebuilt.

Glad you got it sorted out.