You need to Go to the Configuration, turn HTML On, and then in the Allow HTML Tags, put in every HTML tag in that code. Or, just copy the ones I have and use them. I have a lot of HTML tags.
Code:
,i,u,pre,img,center,td,tr,table,p,font,br,a,span,h2,iframe,object,param,embed,li,em,input,blockquote,textarea,h3,h4,form,ol,h1,code
There are many more, but these are the important ones for embedding.