If you have this error in Flash AS3 and Classic ASP, here is the solution:

Error: Error #2101: The String passed to URLVariables.decode() must be a URL-encoded query string containing name/value pairs.
at Error$/throwError()
at flash.net::URLVariables/decode()
at flash.net::URLVariables$iinit()
at sample_fla::MainTimeline/completeHandler()
at flash.events::EventDispatcher/flash.events:EventDispatcher::dispatchEventFunction()
at flash.events::EventDispatcher/dispatchEvent()
at flash.net
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This error, "Error #2044: Unhandled ioError:. text=Error #2032: Stream Error." has been fixed with URL Encode method.

URL Encodes a string

Syntax:

Server.URLEncode( string )

Parameters:
string - string to be encoded

The method returns new string containing URL encoded version of the passed to the method.