Hi?@zaoyao,
Could you please provide us with your website URL and a screen recording showing the steps you took before getting the error? You can use tool such as?https://www.loom.com/?to record your screen.
I’d also suggest to try out safe mode.Go to Elementor > tools , choose “enable” to the Safe Mode setting, and click save changes.
“Safe Mode” is a safe environment that isolates Elementor and WordPress from all themes and plugins, it helps multiple users solve issues like this.
Read about the feature here: https://elementor.com/help/what-is-safe-mode/
If it did help, then there is a plugin/theme conflict that causes this issue, try to deactivate all plugins and turn them one by one till you find the culprit.
Hope it helps.
Kind regards,