I tried that before and it didn't help. I also tried it again this morning and it didn't help. It is like PSE know that I tried uploading these files and it doesn't want me to up upload them again. If I change the file name it works! I don't plan to change the file name on 500 pictures.
Not sure why is that happening that way. Can you give a try renaming the OLS folder present the following location : %appdata%\Adobe\Elements Organizer\10.0\Organizer and then try relaunching Organizer and trying upload of one image?
I tried your suggestion. I renamed the OLS folder to "OLS old" and PSE recreated the OLS folder and I received the following message when I tried to Share to Facebook:
There are no valid files to upload to Facebook. Kindly retry with an appropriate selection.