I'm not sure what's going on, but recently this issue has been appearing while using this plugin which will also in turn make other plugins even utilizing this plugin just cease with this issue. A reload of the plugin until it hits said issue again makes it work, but only for the time being. It can be minutes or even hours until it hits this issue.

Failed to execute OnFrame callback (Specified cast is not valid.)
at void Oxide.Plugins.CopyPaste.PasteLoop(PasteData pasteData) in /home/container/carbon/plugins/CopyPaste.cs:line 1518
at void Oxide.Plugins.CopyPaste.PasteLoop(PasteData pasteData)+() => { } in /home/container/carbon/plugins/CopyPaste.cs:line 1677
at void Carbon.Managers.CarbonProcessor.Update()