An issue has been discovered in the 5.3.6 release that means CSS styling is not applied to emails sent to end users. While the email still works and all information contained within it will be displayed, the lack of CSS formatting can cause it to display in a less than ideal way.
As a result we have issued a hot-fix patch that resolves it.
Apply the Hot-Fix
To apply the hot fix simply download the zip file from the URL below, unzip it, and then upload the file contained within it to the /includes/classes/WHMCS/ folder.
http://docs.whmcs.com/HotFixes#Version_5.3.6
No further steps are necessary.
As a result we have issued a hot-fix patch that resolves it.
Apply the Hot-Fix
To apply the hot fix simply download the zip file from the URL below, unzip it, and then upload the file contained within it to the /includes/classes/WHMCS/ folder.
http://docs.whmcs.com/HotFixes#Version_5.3.6
No further steps are necessary.