HELP-Zotergo doesn't generate bibliography
If I select my pdf-file and click -Create bibliography from Item- it gives me and error with the caption ~The items you have selected contain no references. Please select one or more references and try again.~ What does that mean?
You can try right-clicking on the attachment item and choosing Retrieve Metadata for PDF, but that also would have run automatically when you added the PDF, so most likely that won't work for the PDF in question and you'll need to add a bibliographic item another way. Read through Adding Items to Zotero in its entirety to understand the various ways to get things into Zotero. If all else fails, you can right-click on the item and choose Create Parent Item and enter metadata manually, but that's rarely necessary.
For your existing PDF, right click on it and choose Retrieve Metadata for PDF. If no match is found, right click on it and choose Create Parent Item and then type in the item data. In the future, the best method for adding items to Zotero is using the Save to Zotero button from your web browser.