Default apps error when trying to set file associations, Win 10

[Quadzilla]

Hello everyone , I'm hoping someone can help me out with a problem I'm having installing XNview on my Windows 10 machine
. it's a new PC and I'm not very familiar with Windows 10 , my old PC was a windows 7 machine. I downloaded the
installer and ran it and everything seemed to go fine. I started the program and immediately went to the
settings screen to change the file associations. the first time I clicked the Windows file associations
box, a message popped up saying the app needs to be run as administrator the first time to make this change. So,
I closed XNview , I right-clicked the icon and selected run as administrator. this time,
I got a Windows 10 message you're saying to " to change your default apps, go to settings> apps> default apps." I did this
and changed xnview to the default picture viewer, every time I rerun the program and go to change the Windows
file associations I get that same default application message. FYI, several times throughout this process I rebooted
The PC but make no difference. Please help, thanks in advance for any help you can provide!

[xnview]

on Win 10, you need to change in settings>apps not in XnView's settings

[NormanW]

on Win 10, you need to change in settings>apps not in XnView's settings

I am having the same problem and have spent a day trying to solve it but I am unable to do so.

In Settings> Apps & Features> I do not have an option to change thumbnail settings? Please can you be more specific about EXACTLY what setting in Windows I am looking for to change so that I can see the .CDR (CorelDraw) thumbnails?