This error is the error brought by Firefox while upgrading web components, and that is not affected to the subsequent browser script running on JavaScript main threads. Nevertheless, supressing errors is well-mannered.
When updating the shadow root, we will check whether that is prepared.
Known error NotSupportedError in Firefox will be simply suppressed.
Fix #370.
This error is the error brought by Firefox while upgrading web components, and that is not affected to the subsequent browser script running on JavaScript main threads. Nevertheless, supressing errors is well-mannered.
NotSupportedErrorin Firefox will be simply suppressed.