When attempting to resolve an IPv6 address, either explicitly or by specifying an IPv6 address as the host address when establishing a connection, the method or function fails with an error indicating that the address is invalid. This occurs most commonly on a Windows XP or Windows Server 2003 systems, where the same address can be resolved successfully on a later version of Windows.
When attempting to perform a network operation, such as sending or receiving data, it fails with an error indicating that the operation would block.
When attempting to open a SocketTools example project for Visual Basic 6.0, the error “Class MSComctlLib.ClassName of control ControlName was not a loaded control class” is displayed.
Submitting an e-mail message to a Microsoft Exchange Server is significantly slower than expected, where each message submission can take up to 10 seconds to complete. This problem does not occur when submitting messages to other types of mail servers, including earlier versions of Exchange Server.