I realize this is pretty much standard knowledge for Clarity developers, but it might help someone out there:
In previous versions of Clarity, developers could use simple text and key-tapped special characters in their email notifications in custom GEL processes. As of 13.2, HTML is required for anything beyond basic email text (no carriage returns, indents, etc…).
Email text must be encapsulated in <!CDATA[[]]> tags (example below):
<gel:email from="${EmailFrom}" fromName="${EmailFromName}"
subject="${EmailSubject}” to="${EmailTo }">
<![CDATA[
<html>…stuff goes here…<br>…more stuff…</html>
]]>
</gel:email>
For the sake of saving time I typically a simple online html text editor like the one found here: