I have opened a new group folder in Zotero and I have recently purchased 2gb quota. Whenever I am trying to upload a downloaded file i, I see the upload option in Zotero 7 is not working. Only the web link option is working, the other two option "File" and "Linked File" is not working. I need to upload the downloaded paper as attachments.
Linked fiels aren't available in groups. If the "File" button is greyed out, you don't have files enabled for the group in the group settings on the website. Note that public open groups don't allow files.
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If that's not it, could you describe in a bit more detail what you're trying to do?