I have installed PSE 2021 and performed the Catalog conversion from 2019 to 2021. Result was that the thumbnails, folders etc all there but whe I clickedin to an image I get a grey background with a ? in the centre -ie no image.
So then I created a new catalog making sure my external hard drive (where I keep my images) was mapped.
Same result - All the folders and thumb nails there but same a grey background with a ? in the centre. Why arent my images showing.
My desktop is an iMac currently on 10.15.7 (Catalina) and upgraded PSE so I can install Big Sur