Codemirror editor fullscreen mode
From Joomla! Documentation
Joomla!
3.4.3
In Joomla 3.4.2 we improved the Codemirror Editor there we miss a one line change.
Errors reported[edit]
https://github.com/joomla/joomla-cms/issues/7321
Versions affected[edit]
General Information
This pertains only to Joomla! version(s): 3.4.2 & 3.4.3
What is the cause[edit]
You can't use the Codemirror editor in fullscreen mode.
How to fix[edit]
Apply the patch https://github.com/joomla/joomla-cms/pull/7325.
This will be included in Joomla 3.4.4