J3.x:Change of parameters saving the Codemirror plugin
From Joomla! Documentation
The default values of the codemirror parameters defined in the PHP file are not equal to the default values of the parameters defined in the XML file. The result of this is that on a new installation the active line is highlighted but the XML parameter is set to "no". When you save the Codemirror plugin settings some parameters Change value.
Errors reported
Change of parameters saving the Codemirror plugin.
Versions affected
General Information
This pertains only to Joomla! version(s): 3.7.0 and earlier
How to fix
Solved on Joomla 3.7.0 RC3
N.B. Release Candidates should NEVER be used to update live sites