I am getting 403: Forbidden Access is Denied. when a user accidentally closes their browser without logging out and tries again to open the url.
When they check back, website throws 403. To temporarily resolve the issue I clean out all the cookies and the access is back on.
Error: 403 - Forbidden: Access is denied. You do not have permission to view this directory or page using the credentials that you supplied.
Details to troubleshoot: Web.Config file
<forms loginUrl="index.aspx" protection="All" path="/"
timeout="300"
name="AppNameCookie"
slidingExpiration="true"
defaultUrl="index.aspx"
cookieless="UseCookies"
enableCrossAppRedirects="false"
requireSSL="false"/>
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