Css styles are not applied on Content tab.
It is possible to save invalid HTML from source view in the HTML-editor. Instead of an error message xmlexception appears. Preview of a page can therefore be spoiled by a missing closing tag. This is only an issue when saving changes from source view.
Workaround:
Switch to Visual mode, before saving changes in the HTML-editor.
There is a XML warning message when removing Administrative permission on a page. The warning are correct, but there should be a better explanation to explain the warning.
See knowledge base article How to add css files to C1 UI
The XML preview when running on Composite functions within an XSLT function does not display correct when publishing the “+” signs
Only in FF.