Random COMException on Web App "The handle is invalid"

All of a sudden, I am consistently getting a weird COMException on this machine when I try serve a web app with IIS. I never used to have any problems with this.

Stack Trace:

[COMException (0x80070006): The handle is invalid. (0x80070006 (E_HANDLE))]

[FileLoadException]
   System.ServiceModel.Activation.HttpModule.ProcessRequest(Object sender, EventArgs e) +0
   System.Web.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +68
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +75

How can I fix this? I need this server to be working later today for a demo.

Things I have tried:

• Stop/Start in IIS
• aspnet_regiis -i
• reboot

It is not actually a COM error, it is a Windows error, wrapped in a COM error code. It is a very low-level error, little can be distilled from the error code or the stack trace. There are plenty of hits when you Google the message, here's one that looks good. Be sure to find more yourself if that's not a good match.