I've just installed Office Online Server, following our new Exchange 2016 install. I've set up split dns for oos.contoso.com and have installed the ssl cert for it. All seems to have installed correctly and I can browse to https://oos.contoso.com/hosting/discovery succesffuly but when I try to view a document in OWA I get an error message "An error occurred while the document preview was being created. Please try again later."
I've checked in the error logs and I'm getting log entries to say that it's set up correctly, so I don't know what I'm doing wrong.