Each time I try to save a particular online pdf, Zotero reports an error and I find it in an unrelated collection. I am new, and so while I can add it to the correct collection, I cannot remove the unwanted citation in the incorrect collection without deleting the whole thing. I have searched for this error and read the pdf issues, and this does not appear to have been covered before but my apologies if I am asking the wrong question and a more imaginative search would have given me the answer!