[JavaScript Error: "DuplicateItems must have at least one item" {file: "jar:file:///C:/Users/[…]/AppData/Roaming/Zotero/Zotero/Profiles/shv7q7l1.default/extensions/zoplicate@chenglongma.com.xpi!/chrome/content/scripts/zoplicate.js" line: 2332}]
You're getting an error from the Zoplicate plugin. If this is what you're referring to, you should disable the plugin and report the problem to the plugin's developer.
Upgrade Storage
Sorry for the inconvenience. This issue has been fixed in [version 3.0.5](https://github.com/ChenglongMa/zoplicate/releases/tag/3.0.5).
Thanks for the feedback!
Best regards,
Chenglong