I'm having the same exact problem! What is Microsoft doing to fix this? It has been working fine for over 20 years and all of a sudden I can't use Windows Photo Viewer or One Photo Viewer or even others. The only way for me to view a photo is to view it within Photoshop. EEEERRRRR!
I've been having this issue since shortly before installing the latest Windows Update last week. Any time I click on a photo within Windows Explorer, a message pops up that simply lists the file path and says "Not Implemented".
This started happening before I installed the update, and it was only upon restarting my computer to solve the issue that the update was installed (I tend to procrastinate updates).
The issue appears to be caused by Explorer. Downloading any random image with my Chrome browser and opening the image from the downloads list successfully opens the image, as does viewing images from within the Photos app itself.
Restarting Explorer from task manager fixes the issue temporarily, but it has always reoccurred after some time. So that's not a permanent fix and having to restart Explorer at least once a day is not ideal. I'm more just worried that this could be the precursor to or symptom of something much more serious. I've never had this problem before, and most issues like this are resolved with a full restart.
I don't know what to do.