Microsoft’s recent Patch Tuesday brought four critical updates, as well as eight important updates, in an attempt to resolve 54 reported vulnerabilities found in Microsoft Windows and Microsoft Office. KB 3097877, part of security bulletin MS15-115, was found to cause a multitude of issues for those using Outlook, including the following:
Crashing when opening web-formatted (HTML) emails
Black screens when trying to log in
Other odd behaviours/general hangups
Upon discovering the issues, a spokesperson from Microsoft explained, "We are looking into reports from some customers who are experiencing difficulties with Outlook after installing Windows KB 3097877. An immediate review is under way.