Microsoft Dynamics GP 2013 Web Client Unexpected Error

I restarted the virtual machine running the Microsoft Dynamics GP 2013 Web Client and tried to login but got the beow error message;

An unexpected error has occurred. Press the Sign-in button to reconnect to the application. Correlation ID: 99259225-b352-b163-b7c1a166e06c

I did a little investigation and found that when the virtual machine had started the GP Session Central Service had not;

I clicked Start and the service started without problem and I was able to log into the Web Client.

I’ve restarted the server a couple of times since then and not had a repeat of the problem so it looks like a one off. But if I do see Unxpected Error I know where to start looking.