To enable the Skyat/spell checker plugin for Sage CRM editors you must change the default CKeditor configuration file.
This file is called config.js and it is found in C:\Program Files (x86)\Sage\CRM\CRM_INSTALL\WWWRoot\ckeditor
Add the following lines:
1. config.scayt_autoStartup = true;
2. add 'SpellChecker' and 'Scayt' to the items property on any of the existing toolbars;
toolbar without spell checker