Why can't I see ALL my thumbnails since updating my iMac OS to Catalina?

[iMore Question]

I have just updated my iMac operating system to Catalina. Since doing so, Preview doesn't appear to be working properly. I can see SOME of my images thumbnails but most of them appear as a Camera lens blades icon. If I double click on the image it will open as normal in Photoshop but going through hundreds of images I need to be able to see the image thumbnails. I have unplugged the power and reconnected after 10 minutes. No change. Opening up in safe mode still produces the same problem. I'm presently backing up my system with Time machine before I attempt to restore the OS that was on my iMac before Catalina. Anyone any ideas on this?

 

[Just_Me_D]

Can you try reinstalling Catalina?