Came across the recent Invalid photo (CLERR002) error message on my mac running Big Sur version 11.1 and it drove me crazy. I found out that my photos needed to be a maximum size of 1600x1600 or less.
Found 2 different ways to fix it.
1) If you use an iPhone to take your eBay photos with go to the Settings App-->Select Camera-->Select Formats-->and then select Most Compatible. (you can also make sure that the "View Outside the Frame" icon is unchecked as it will help with photo sizing)
*If using an Android you should be able to use a similar process to this.
If the above doesn't work you can reformat your images you could try this:
2) On a Mac, select/highlight all the photos you want to load onto eBay-->Click on one of the photos so the Options Dropdown Menu Opens-->Select Edit With-->Then Preview. When Preview opens up and all your photos are loaded-->Highlight the photos in the side bar-->On the top Toolbar select "Tools" then "Adjust Size"-->Select Custom-->Unlock the Mini Lock Icon-->Change Width to 1600 and Height to 1600-->Set the size type to Pixels-->Select OK.
It may take a moment for the photos to reformat. Now you shouldn't have any issues. Hopefully either one of these options will work for you.
