Report ID: 1406043585 "An error occurred while saving this item."
Just downloaded Zotero to my new computer. Entire library is gone and when I try to save any articles I get the error message "An error occurred while saving this item. Try again, and if the issue persists see Getting Help for more information."
You say the "entire library is gone", but if this is a new computer, you just need to sync Zotero to get the data on this computer. If you don't see your data in your online library on this site, that means you haven't synced properly from your old computer.
Next, and unrelated to that, if you're having trouble saving from the browser, see Troubleshooting Translator Errors. We'd need more info if you're still having trouble, as explained there.
Finally, you're getting a specific error in Zotero that will prevent attachments from being saved: The university's proxy server is misconfigured, and this will prevent you from saving gated PDFs. (Items themselves will still save to Zotero — they just won't have attached files.) The IT department should fix this, but you can work around it by saving the university's homepage to Zotero once. Since the homepage is configured correctly and uses the same intermediate certificate, Zotero will store the intermediate certificate and use that when you try to save files via the proxy in the future.