Resolved: The issue with Microsoft Outlook web access has been corrected by the vendor.
November 8, 2017 07:54pm Intermittent Issues with Outlook Web Access
A recent vendor update is affecting Microsoft Outlook web access. Some users may experience intermittent issues opening a new message or new reply message. Microsoft is in the process of rolling back the patch. Updates will be posted as they become available. In the interim, users may be able to access content using the Outlook client as an alternative method.