Scaffolding add-on is suspected to cause page restoration to fail. When restoring older pages from Page History > Restore, it failed and user would see the following error:
Enable Safe Mode followed by enabling only Scaffolding and ServiceRocket Utility Library plugins. Verify if the issue is still reproducible with only Scaffolding and ServiceRocket Utility Library plugins enabled.
groovy-all v2.1.6 makes a call to conveyor class in ServiceRocket Utility Library plugin utilised by Scaffolding which then affected page restoration process and subsequently caused it to fail
Uninstall groovy-all v2.1.6 plugin from Plugin Manager followed by Confluence restart. The issue would then be resolved.