Hi Larry and thanks for the reply. I did try to migrate from iPhoto but this only pulled across most of my early stuff then there was a gap of about five years then most of the images dating from 2012 onwards were migrated. I tried running the migration again and only wound up pulling across the same images resulting in duplicating everything.
I decided to delete all the images stored in iCloud and started again. The migration then failed with the error message
"Uploading folders isn't supported. Only files in JPEG format can be uploaded"
I thought about this for a while and wondered if somehow I'd managed to post a clump of pictures into iPhoto in a folder. I couldn't see any obvious folders so I used the upload tab in iCloud>Photos to import images in batches waiting for the import to fail. This it did after successfully uploading all the images to end mid February 2006 at which point I thought I'd isolated the issue but none of the images past mid February would upload despite me editing some to absolutely insure they had the right extension and trying to upload images singly.
At that point I made this post following which I tried the exercise using Chrome to access iCloud. I have no understanding of why but as I type this images are being happily uploaded to my iCloud account.
So I've just concluded it's one of those little bugs that occasionally interrupt the smooth flow of Apple endeavour but I am intrigued that I can find no trace of others having s similar problem.
Peter
