Cant set column content

[Eddcapone]

I try to add a row or column with wysiwyg Editor with my custom HTML. But if I create it and add my html and press on "Insert Widget", then nothing is getting saved and it is just like at the start before I did my changes.

Once I got this error:

I am using Magento 2.3.4

[mirabon]

I try to add a row or column with wysiwyg Editor with my custom HTML. But if I create it and add my html and press on "Insert Widget", then nothing is getting saved and it is just like at the start before I did my changes.

Once I got this error:

I am using Magento 2.3.4

Check enabled or not WYSIWYG Editor by default (https://docs.magento.com/user-guide/cms/editor-configure.html). Need enabled