Hi Paul,
It will not be about creating a new page yes or no. It is the content you pasted from Microsoft Word.
It was pasted from Microsoft Word. JCE Editor or no JCE Editor. That is what is causing the error. So the essence of solving the problem is deleting the existing content and putting new (not pasted from Word) content there. Wether you do that through a new article or not, that doesn't matter. Just get rid of the stuff you pasted with Word.
In my 5 years of working with Joomla I have learned 1 thing. Microsoft Word and Joomla do not go well together