XnView Software

When you try to add XMP metadata for PNG files nothing is saved:
how to reproduce:
1. open PNG with no metadata
2. try to add some xmp fields (I tested with title and author)
3. push apply or write, open dialog again and you will see empty fields
4. same if you try save as new png file with different name. nothing is writed

but if you try to change metadata in files with already existed metadata everything will write correctly
and if you export jpeg to png, xmp persisted too

XnViewMP 1.3.1
Windows 11 22H2 x64

i can't reproduce, you use 'Edit XMP' from browser right?

1. Open XnView
2. From Browser open test.png
3. Edit XMP and add autor, title...
4. Click Apply
5. Click again Edit XMP or save file as test2.png
---> No XMP info was written.

And now, after save test2.png if You Edit XMP this file from Browser, add something and click save --> test2.png disappears from Browser (but not from folder and XMP are saved).

Bug is only after start XnView.

Thanks to your detailed description I can reproduce the problem.

This problem is supposed to be fixed in XnView MP 1.4.0. Please check and confirm the bug fix here.