Can't Connect to Machine via Remote Desktop

I had a machine I could not Remote Desktop (RDC) to. No matter what I did, I got the same error:

The connection was ended because of a network error. Please try connecting to the remote computer again.

In the System event log on the machine I was trying to connect to, I found quite a few Error entries with the source TermDD. This described the following error:

The RDP protocol component "DATA ENCRYPTION" detected an error in the protocol stream and has disconnected the client.

After a quick search, I found the following Microsoft KB article that helped me fix the problem:

"The RDP Protocol Component "DATA ENCRYPTION" Detected an Error..." error message

A reboot on the machine and it is now working fine.