“Invalid data Current stte has involved an issue” error

Hi,

Please tell me where it only appears on one page or the entire site. Did you add any code or elements from another plugin?
Please follow the steps from this topic https://forum.tagdiv.com/topic/error-at-zones-6models-1dom-the-model-does-not-match-the-content-currene/ if you have a child theme; please use the main theme.
You can try to revert an old revision on a page/template -> https://www.wpbeginner.com/beginners-guide/complete-guide-to-wordpress-post-revisions/

Thank you!