Exchange 2010 OWA failure

Had a call about an older Exchange 2010 server this morning. Users were having problems working with Outlook Web App.

I saw a high volume of errors in that Application event log. This error was referring to both autodiscover and '/EWS/Exchange.asmx' and was appearing multiple times per minute.

Event ID: 3
Source: System.ServiceModel 3.0.0.0
Category: WebHost
WebHost failed to process a request.
 Sender Information: System.ServiceModel.ServiceHostingEnvironment+HostingManager/32001227
 Exception: System.ServiceModel.ServiceActivationException: The service '/Autodiscover/autodiscover.xml' cannot be activated due to an exception during compilation.  The exception message is: This collection already contains an address with scheme http.  There can be at most one address per scheme in this collection.
Parameter name: item. ---> System.ArgumentException: This collection already contains an address with scheme http.  There can be at most one address per scheme in this collection.

There was also this error about OWA.

Event ID: 108
Source: MSExchange OWA
Category: Configuration
Outlook Web App couldn't connect Exchange Web Services due to a configuration error. Response code = "null, webException.Status = SendFailure".

The errors in the log began at about 12:15am when someone had done a server reboot. So, something in that reboot triggered the issue. My first thought was updates, but no updates had been applied recently.

After a bit of research, it turned out to be the bindings for the default web site causing the issue. At some point, someone had added additonal http and https bindings to the default web site. When I removed the additional http and https bindings everything started properly and the errors no longer appeared.

I am guessing that someone added those bindings a long time ago, but they didn't start causing the issue until IIS was restarted as part of the reboot.