why i get this error sometimes?

[mastermehdi]

hi

when i use radajax in my login panel, sometimes i get this error message:

System.Web.HttpException (0x80004005): The length of the query string for this request exceeds the configured maxQueryStringLength value.
 at System.Web.HttpRequest.ValidateInputIfRequiredByConfig()
 at System.Web.HttpApplication.ValidateRequestExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
 at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)
at http://elix.ir:80/WebResource.axd?d=QKIdEQgXIJhOS6nEbL0GA26gwLz8CyDbQ0NK4tfT_ytfAlSrNGAKsRkbQ4C-u8a8Y6_H-6xgUpTGI4yt7wCD7YBt,%20'ctl00_btnLogin')">خلاصه%20وضعیت
ارسال%20آگهیدریافت%20آگهیواریز%20به%20حساببرداشت%20از%20حسابپیام%20های%20دریافت%20شدهارسال%20پیام%20به%20سایتویرایش%20مشخصاتخروجاطلاعاتامروز:%20یکشنبه%201390.2.4تبلیغات%20امروز:تبلیغات%20دیروز:45,982%20نمایش799%20کلیک35,875%20نمایش910%20کلیکواریز%20به%20حساب
تمامی%20حقوق%20این%20سایت%20محفوظ%20و%20متعلق%20به%20شرکت%20چکاوک%20ایده%20پرداز%20می%20باشد.

my code is:

<tlk:RadScriptManager ID="radScriptManager" runat="server" />
<tlk:RadAjaxManager ID="radAjaxManager" runat="server"
    DefaultLoadingPanelID="radAjaxLoadingPanel">
    <AjaxSettings>
        <tlk:AjaxSetting AjaxControlID="pnlLogin">
            <UpdatedControls>
                <tlk:AjaxUpdatedControl ControlID="pnlLogin" />
            </UpdatedControls>
        </tlk:AjaxSetting>
    </AjaxSettings>
</tlk:RadAjaxManager>
<tlk:RadAjaxLoadingPanel ID="radAjaxLoadingPanel" runat="server"
    InitialDelayTime="500"
    Skin="Default">
</tlk:RadAjaxLoadingPanel>
<asp:Panel ID="pnlLogin" runat="server"
    DefaultButton="btnLogin">
    <div>
        <asp:Label ID="lblUsername" runat="server"
            AssociatedControlID="txtUsername"
            Text="username " />
    </div>
    <div>
        <asp:TextBox ID="txtUsername" runat="server"
            MaxLength="50"
            style="width:175px;" />
    </div>
    <div>
        <asp:Label ID="lblPassword" runat="server"
            AssociatedControlID="txtPassword"
            Text="password " />
    </div>
    <div>
        <asp:TextBox ID="txtPassword" runat="server"
            MaxLength="50"
            style="width:175px;"
            TextMode="Password" />
    </div>
    <div>
        <asp:Button ID="btnLogin" runat="server"
            CssClass="btn"
            OnClick="btnLogin_Click"
            Text="login"
            ValidationGroup="login" />
    </div>
</asp:Panel>

i use Telerik.Web.UI v2011.1.322.40

What is the reason for this error and how i can fix it?

[Daniel]

Hello,

I recommend that you examine the following link:
System.Web.HttpRequest.ValidateInputIfRequiredByConfig() +8884093

Regards,
Daniel
the Telerik team