Can you please display (or write to file) the following information (before you initialize Rebex classes) and post it here?
string.Format("{0} {1} {2}",
Environment.OSVersion.Platform,
Environment.OSVersion.Version,
Environment.Version)
Maybe, you are running .NET CF 3.9 or 2.0?
Update: Actually, this error is raised by .NET CF edition of Rebex HTTPS if it's running on a platform other than .NET Compact Framework. For example, it would occur when running Rebex binaries for .NET Compact Framework 3.5 on .NET Framework 3.5 or .NET Framework 3.5 Client Profile.