Thanks for your replies. There isn’t much a screenshot would show apart from a banner across the top of the page with the posted text in it and a completely blank editing screen. I am unable to add anything to the screen.
We do, however, use a custom theme built specifically for our company. I don’t know who designed or built it but reading some of the other forum posts it could be this. I have no idea how to update a purpose built theme but if there is someone out there who is willing to assist in rectifying this issue, please contact me.