Hi Joe
I was trying to work out why a site using TinyMCE refused to allow links to open in a new window (bearing in mind your opinions on this subject ;-), and found a small config error. This line in mojoTinyMCE4.config has typos highlighted:
ExtendedValidElements="iframe[src|width|height|style|name|title|align|scrolling|frameborder|allowtransparency],meta[itemprop|content],link[itmeprop|href|class|onclick],a[itmeprop|href|class|onclick]"
And to permit the target attribute (which seems polite given the editor allows the user to specify this for a link):
ExtendedValidElements="iframe[src|width|height|style|name|title|align|scrolling|frameborder|allowtransparency],meta[itmeprop|content],link[itemprop|href|class|onclick],a[itemprop|href|target|class|onclick]"