The issue is caused by a setting within Internet Explorer that forces a Certificate Revocation check for the certificate used to sign the code in the Powershell script.
You can turn off this checking by following the steps below.
- Open Internet Explorer
- Go to Tools > Internet Options
- Select the Advanced tab
- Scroll down to the Security section. Uncheck the option to Check for publisher's certificate revocation
For security reasons it is not recommended to leave this setting unchecked, especially if the server has Internet access.
I have come across this problem on Windows Server 2003 and Windows Server 2008 R2 platforms.