Error: Redirect URI cannot contain newline characters.

Can anyone please give me a suggestion how to solve this problem? When I accessed the workspace sometimes it worked, sometimes I got the error as following.

Server Error in '/K2V3/Workspace' Application.

Redirect URI cannot contain newline characters.
Description: 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.

Exception Details: System.ArgumentException: Redirect URI cannot contain newline characters.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:

[ArgumentException: Redirect URI cannot contain newline characters.] System.Web.HttpResponse.Redirect(String url, Boolean endResponse) +539 System.Web.HttpResponse.Redirect(String url) +7 Workspace.Net.WorkSpace1.Page_Load(Object sender, EventArgs e) +593 System.Web.UI.Control.OnLoad(EventArgs e) +67 System.Web.UI.Control.LoadRecursive() +35 System.Web.UI.Page.ProcessRequestMain() +731

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

Thanks a lot,