I just upgraded my DNN 4.7 to 4.9 on my localhost machine, I did it twice to be sure the problem stays the same and it does.

I did everything that everyone suggest here and other places like MitchellSellers and etc.

Everything went smoth like they said it would and got these results:

Upgrade Status Report

00:00:00.015 - Upgrading to Version: 4.9.0
00:00:00.250 -   Executing Script: 04.08.00.SqlDataProvider Success
00:00:11.265 -   Executing Script: 04.08.01.SqlDataProvider Success
00:00:11.500 -   Executing Script: 04.08.02.SqlDataProvider Success
00:00:11.609 -   Executing Script: 04.08.03.SqlDataProvider Success
00:00:11.625 -   Executing Script: 04.08.04.SqlDataProvider Success
00:00:11.625 -   Executing Script: 04.09.00.SqlDataProvider Success
00:00:11.796 - Performing General Upgrades
00:00:12.796 - Installing Package File LiveID_01.00.00_Install:  Success
00:00:13.203 - Installing Package File OpenID_01.00.00_Install:  Success
 

Upgrade Complete

My website is running and so far all the modules seem to work.

The problem is that none of my ADMIN or HOST menu options are working, anything I click on I get to "CANNOT DISPLAY WEBPAGE" page.

How do I get to work? Anyone else had this problem? Please help.

PageBlaster is the only one I can think of.

I had the very same problem with one of our clients. It turned out that they had to go into the tabs table and set the column IsSecure = 0 (false). That helped for them.