We have 1 user that's getting the error, "The Microsoft Exchange administrator has made a change that requires you quit are restart Outlook." It happens when she's in Outlook and goes from her email to the calendar. It doesn't happen every time she does that but it happens 2-4 times a week. Sometimes, it will freeze up Outlook and she will have to restart it but other times, she can just click OK on the message and it will let her in the calendar. It's not a huge issue but is kind of pain and I'm not sure why it's only happening to 1 user. We're running Exchange 2016.