can't add downloaded files

I can no longer add PDFs or other downloaded files to my Zotero libraries. I haven't run out of storage yet. I can still add items with the Zotero extension in my browser, but I can't drag and drop PDFs anymore. Similarly, when I go to the green + and then Store Copy of File, it says, "You cannot add files to the currently selected collection."
Sign In or Register to comment.