Could someone please tell me what this error means. I am running suse 10.3 and installing from ifolder.com

Server Error in '/ifolder' Application
A potentially dangerous Request.QueryString value was detected from the client (Exception="System.Web.Comp...").

Description: HTTP 500. Error processing request.

Stack Trace:

System.Web.HttpRequestValidationException: A potentially dangerous Request.QueryString value was detected from the client (Exception="System.Web.Comp...").
at System.Web.HttpRequest.ThrowValidationException (System.String name, System.String key, System.String value) [0x00000]
at System.Web.HttpRequest.ValidateNameValueCollection (System.String name, System.Collections.Specialized.NameValueCollection coll) [0x00000]
at System.Web.HttpRequest.get_QueryString () [0x00000]
at Novell.iFolderApp.Web.Error.Page_Load (System.Object sender, System.EventArgs e) [0x00000]
at System.Web.UI.Control.OnLoad (System.EventArgs e) [0x00000]
at System.Web.UI.Control.LoadRecursive () [0x00000]
at System.Web.UI.Page.ProcessLoad () [0x00000]
at System.Web.UI.Page.ProcessPostData () [0x00000]
at System.Web.UI.Page.InternalProcessRequest () [0x00000]
at System.Web.UI.Page.ProcessRequest (System.Web.HttpContext context) [0x00000]

Version information: Mono Version: 2.0.50727.1433; ASP.NET Version: 2.0.50727.1433