@Jason NG I was unable to reproduce this error in a local installation of Fleet. I’ve adding this to the following issue on GitHub that tracks what you were seeing:
https://github.com/fleetdm/fleet/issues/1704
Note: I’m using Fleet 4.2.2 (released yesterday 8/18)
If you encounter this issue during your next upgrade, can you please include a screenshot of the contents of your browser’s JavaScript console? This way, the Fleet team can identify if the issue you’re encountering on a frontend.