Any changes to the themse gives an error message "Setting content is invalid".

The error message:

Setting 'content' is invalid. All top level nodes must be '

', '

', '
' or '# '-'###### ' tags and Attribute 'data-mce-fragment="1"' is not permitted on tag '<strong>'

No changes i make to the theme is saved.

Any ideas?

My store: https://zfuzrx1frtaou8o1-62297047214.shopifypreview.com

https://gyazo.com/c553cbaf394bc57f4cecd687023e6769

Any changes I make on the theme gives this error. Even changing a text anywhere.

I’m constantly getting the same error without a clear reason too.