I upgraded to Photoshop Elements 2020 a few months back and ever since all 39,000 photos on my mac can only be viewed in "grid" form. If I try to select one to view, I just get a big blank with a question mark. To add insult to injury, when I go on the website to get help, I'm told I dont have a product registered dispite the fact that I can find it on the Adobe website as registered. This is an epic fail and an absolute joke on the part of Adobe. I'd laugh about it and walk away from these products forever if I could only figure out how to restore my photos.
Keep in mind that this is first and foremost a user forum where users try to help each other. Reason I say this is because you're not exactly giving us much information to work with in order to try and resolve the issue. First: from whiich version did you upgrade? And what are the specs of your Mac?
To be honest I also don't understand why you'd bring up this issue only months after it happened, or is my impression incorrect? Because that too might give us leads as to the possible cause here.