saving an article produces fault content (code/data-gutter)

Hi
if the code is already saved into your article, you must use the article versioning to get an eearlier version where you don't have the problem
then you can save it as you have setup the text filter

for info, if the text filter is not set correctly you shall have seen a red alert message

Thanks for the answer!
I opened a completely new article, but the entire formatting disappears there as well. No red error message is displayed.
I also checked (attached) the settings. I turned off text filtering in settings and in TinyMCE as well.

please send me an admin access by email so that I can check the problem
www.joomlack.fr/en/contact