This error has been plaging me since around 2.3.3 whenever I create pages with custom content, various sites on various servers. Is there a way to see what the errors are?
In todays case, I've created a custom HomePage class with a couple of extra content sections, and it won't save. One of the attempts it told me to log out and try again, so I did and still no saving.
If I convert the new sections from HtmlEditorField to TextareaField it saves again, but I don't want TextareaFields, so it's probably something wrong with that.
I'm using 2.4.0