Server side error?

In searching some books on line, I got "Server Error in '/' Application." page, describing as, "An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code."
And Source Error and Stack Trace description lines are on the page. At the end of the lines,

Version Information: Microsoft .NET Framework Version:1.1.4322.573; ASP.NET Version:1.1.4322.573

Huu, OK.