need to add these lines in web.config file...

<!-- note: after </runtime> and before <system.webServer> -->

<location path="ReportPDF">
		<system.web>
			<authorization>
				<allow users="*"/>
			</authorization>
		</system.web>
</location>
<system.web>
		<authentication mode="Forms">
			<forms loginUrl="/Pages/Default.aspx" defaultUrl="~/Pages/Default.aspx" timeout="2880"/>
		</authentication>
		<authorization>
			<deny users="?"/>
		</authorization>
		<globalization requestEncoding="UTF-8" responseEncoding="UTF-8"/>
		<pages smartNavigation="true" validateRequest="false" enableEventValidation="false" viewStateEncryptionMode="Never" controlRenderingCompatibilityVersion="3.5" clientIDMode="AutoID">
			<controls>
				<add tagPrefix="asp" namespace="System.Web.UI.DataVisualization.Charting" assembly="System.Web.DataVisualization, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
			</controls>
		</pages>
		<sessionState cookieless="false"/>
</system.web>
<location path="Pages/DefaultReport.aspx">
		<system.web>
			<authorization>
				<allow users="*"/>
			</authorization>
		</system.web>
</location>

<!-- note: after </runtime> and before <system.webServer> -->