Odd blocking and discoloration around Pictures when viewed on computer from R5 Mark ii

[Far-Out-Dude]

Odd blocking and discoloration around Pictures when viewed on computer from R5 Mark ii when view on the computer. I never had this problem when I loaded to my computer with the M50 so I am unsure why this is doing this but it makes it hard to choose pictures to edit. It does not show when I go into Lr or in the Canon program but I don't want to load hundreds of pictures into Lr and the Canon program makes no sense to me and I can't find a selection to move pictures to Lr that I like. I have included some pictures. Also some pictures are not showing up full sized on the computer. Thank you for any help given.
OddColors.jpgThumbnailsized.jpg

[Peter · Accepted solution]

Have you tried FastStone Image Viewer instead of Microsoft's image viewer? Should be what you are looking for.

[Far-Out-Dude]

No, I have never heard of it. I will try. Thank you.

[Far-Out-Dude]

That's worked! Thank you so much!