XnView Software

When thumbnails per page starts with 4, every 5th thumbnail is missing.
So it looks like the program wants to put 5 on a row, but the 5th falls of the sheet.

Now it gets complicated:
(all tests done with 6 rows, and only previewed, 16 thumbs selected)
5x6: OK, 16 shown
6x6: OK, 16 shown
7x6: not OK, 14 shown, no. 8 and 16 mising
8x6: not OK, no. 9 missing, so 7 on second row
9x6: not OK, no. 10 missing

Important: This only happens when selecting paper size Letter, Legal, A4 or A3. When selecting 4x6 through 11x14 all the thumbs are show in the preview.

Confirmed. Good that you found this bug, HanVroon.

This problem is supposed to be fixed in XnView MP 0.85 beta 3. Please check and confirm the bug fix here.

Tested in 0.85 beta 3, partly fixed.
No missing thumbs anymore, but two new things.
I report them here because it all seems to deal with the same thing, calculations in combination with margins.

This morning I saw that I could get all the thumbs selected on the sheet in beta 2 by entering horizontal spacing for the thumbnail. At 4 pixels and more all thumbs were displayed, from 0 to 3 pixels not.

Now, with beta 3, all the thumbs are always displayed, but:
(asume thumbnais are set to 4 x 4 per page)
With all margins (sheet and thumbnail) set to 0, at the right side there is a white space along the sheet. That was'n the case in beta 2.
When entering horizontal space at sheet level, starting with 1 pixel already, there will be 3 thumbs on a row instead of 4 (thumbnail margins still at 0 x 0).
When enetring also horizontal space at thumb level, just 1 pixel is enough, there are 4 thumbs on a row again, as should be.
So there are some calculation errors in combination with margins.

yes, you can have a small spacing at the right. For example, you want a width of 1023 px, and 4 thumbnails, so the size of each thumbnail if 255, but you have a spacing of 3px (1023-4*255)

OK, got that.I had set paper size to A4, got width 595 pixels. When I change that to 596 it can be devided through 4, so no white space.

Did you look at the other point I mentioned:
When entering horizontal space at sheet level, starting with 1 pixel already, there will be 3 thumbs on a row instead of 4 (thumbnail margins still at 0 x 0).
When enetring also horizontal space at thumb level, just 1 pixel is enough, there are 4 thumbs on a row again, as should be.
This now starts at 2 pixels instead of one (?).

To reproduce:
1- Select 8 thumbs
2- Use program defaults (1024x1024, 4x4 thumbs, sheet margins and thumbnail margins all on 0.
3- Preview will show 2 rows of 4 thumbs.
4- Set the sheet marin width at 2 pixels (or more).
5- Preview will show 2 rows of 3 thumbs and a 3rd row with the last 2 thumbs.

I would expect the thumbs to shrink a little and still 2 rows of 4 thumbs.

Fixed in 0.85 beta 4
Now look OK. Tested with all kind of margin settings on sheet and thumbnail, the amount of thumbs is always according to Thumbnails per page setting.