Board Thread:Support Requests - Getting Technical/@comment-25050081-20151029094748/@comment-5062941-20151029130000

Per Oct. 26 Tech Update, template editors have been changed to syntax highlighted editors. But you can check "Do not show syntax highlighting in Source mode" under Editing experience in your Preferences to revert it back. It's not the "Migrate this infobox" that's causing it :)