"Connection failed to url. The underlying connection was closed: Could not establish trust relationship for the SSL-TLS secure channel" error in SAM

10/10/2018 2:29 PM

7/31/2025 10:09 PM

The following error is encountered when using the OWA Form Login monitor:

The "Exchange 2010 OWA Form Login (PowerShell)" Application fails with the following error: "Connection failed to URL.  The underlying connection was closed: Could not establish trust relationship for the SSL/TLS secure channel."

Server Application Monitor

The System.Net.ServicePointManager.ServerCertificateValidationCallback object is disabled in the PowerShell script. 

Modify the Windows PowerShell monitor script within the "Exchange 2010 OWA Form Login (PowerShell)" application to enable the System.Net.ServicePointManager.ServerCertificateValidationCallbackobject from:
 

#This command set the static property in .NET that causes the error in HTTPS probes.
#[System.Net.ServicePointManager]:ServerCertificateValidationCallback = {$true}

to
 

#This command set the static property in .NET that causes the error in HTTPS probes.
[System.Net.ServicePointManager]::ServerCertificateValidationCallback = {$true}

Note: A problem in the .NET implementation may cause HTTPS monitors to fail with the following error when the OWA script is used with other HTTPS monitors:

Unexpected error occurred. The underlying connection was closed: An unexpected error occurred on a send.

To prevent this, switch all HTTPS processes to 64-bit mode and keep the OWA PowerShell script running in 32-bit mode:

1. Go to Settings > SAM Settings > Manage Application Monitors.

2. Select the application that contains the HTTPS component and click Properties.

3. Open the Advanced section and set the Platform to run polling job on to x64.

4. Click Submit.