You will have to restore the settings of the DualShield IIS Agent first, then re-apply the settings.
Step 1: Restore Settings
You can restore the DualShield IIS Agent settings in 2 ways, restore by GUI or by PowerShell script.
On the Exchange CAS server, launch a PowerShell window, navigate to the folder:
C:\Program Files\Deepnet Security\IIS\DasWeb
Then, execute the PowerScript below:
If you get some errors then it means that the name of the web site affected is not "Default Web Site".
In this case, you need to edit the line below in the script:
$metapath = $item.path -replace "/LM/W3SVC/1/Root/", "MACHINE/WEBROOT/APPHOST/Default Web Site/"
You need to replace the text "Default Web Site" with the correct web site name. You might also need to replace the text "/LM/W3SVC/1/Root/" if you have multiple web sites running on the same server.
Once you have made and saved the changes, execute the PowerShell script again.
Step 2: Re-Apply Settings
In the IIS Manager, select to a node that's enabled with DualShield 2FA, e.g. RDWeb.
On the right pane, double click the DualShield icon to open its settings
Click the "Change” button in the “SSO Server” section:
In the SSO Server Settings windows, untick the “Enable Proxy” option:
Then, click “Apply” to save the changes
Now, go back to the “SSO Server Settings” and tick the “Enable Proxy” option:
Then, click “Apply” to save the changes.