1. Use Internet Explorer to access the same URL as stated which is http://yourIISserver/PowerShell. It should give more information on why the console is having issues accessing it.
2. Once you know why IIS is rejecting the access, check IIS log in C:\inetpub\logs\LogFiles\ for more detail by looking for the keyword 'PowerShell'
In my case, the issue was because the server was using IPv6 address which is not in my list of allowed IP addresses.
The above error is IIS related. Basically the console has problems accessing PowerShell via IIS. While the cause may not be the same for you, the steps above may shed more light into it.