CRM 2011 - A Sandbox Host is Not Available

Gayan Perera, 13 February 2013

Production environments have hardened security. If you’ve recently installed CRM on one of these environments you might come across this error:

A Sandbox Host is not available
Source: w3wp.exe (3940)

 Sandbox Host: XYZ

 Reason: System.ServiceModel.EndpointNotFoundException: Could not connect to net.tcp://xyz/CrmSandboxHost. The connection attempt lasted for a time span of 00:00:21.0254298. TCP error code 10060: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond x.x.x.x:808.

The reason is that port 808 is not open on your backend server that’s running the sandbox service.

To fix this issue simply create a firewall rule to allow inbound TCP traffic on port 808.