"Cannot edit the original file; a copy was created with your changes" OS X

macOS 10.12.1; Zotero Stendalone 4.0.29.15; system Preview to open pdf.
I used to open pdf via Zotero and make annotations in Preview and there was no problem with saving. I dont know if it's a coincidence or a cause but since installing LibreOffice and appriopriate zotero plug-in I get the above massage that effectivly prevents me form saving the changes in Zotero pdf library. Roundtrip with adding annotated pdf back into the library is not an option. Can anyone please help?
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