Thanks for the quick response. It occurs when I go into the Media Library and add then edit a new image or edit an existing one. The edit page comes us correctly initially, with the custom fields, but clicking any of the checkboxes causes it to reload and lose the custom fields. I have the fields divided into three tabs, if that makes any difference. Like TimTee above, I’ve switched to a multi-select field as a stopgap, and that works but it’s not as good.
There’s no POPUPs involved, as far as I can see, but I may not be understanding your question.
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