Its nothing to do with mso-bidi-font-family being an 'invalid' HTML attribute.  Its to do with the comma as the following also raises the error.   <span style=''font-size: 12pt; font-family: 'Times New Roman'''>Content</span>   Is there a simply way to escape the commas for the spell check?

Hi Adam,   Thanks for the reply.  Have narrowed the error down and tested in the above example.  Problem is with the html:   <span style=''font-size: 12pt; mso-bidi-font-family: 'Times New Roman'''>Content</span>    Perhaps it has something to do with the 'Times New Roman' not being escaped properly?

I'm having some trouble with the spellcheck functionality where it is reading the styling of html elements to populate its word list.   i.e. with the html element '<span style=''font-size: 12pt''>Content</span>' it is picking '12pt' up as a word for the user to check.   Does anyone know why this is happening and how to ...