Option 1Package Creation:
To resolve this issue go to Settings > Packages > Advanced Settings and set JSON to “Custom”. After that, rebuild the package to see if the issue goes away.Note: This setting is only available in Duplicator Pro.
Option 2Setting Migration:
If you are using the settings migration export tool and see this error then data stored in the settings, templates, storage or schedule area has become corrupted. Check the data in thefailed area to make sure the data is correct. If the data looks correct consider re-saving the data in that respective area. If the problem persists consider removing the items one byone to isolate the setting that is causing the issue.