Internet Explorer "Page Cannot be Displayed" error due to Bad Proxy Server Timeout

KB Article: https://support.microsoft.com/kb/2551554

INTRODUCTION

In very rare scenarios, it is possible for certain server connection errors to result in proxy servers being added to the bad proxy list incorrectly, causing Internet Explorer to rotate through the specified list of proxy servers until all are temporarily disabled. At this point, Internet Explorer will show a “Page Cannot be Displayed” error until the bad proxy list is cleared (30 minutes later by default).