Forum Discussion I have an Exchange 2013 server running on Server 2012 R2 that I am trying to migrate to Exchange Online with a hybrid configuration. I have setup the AD Connect without an issue. However, before I installed the HCW, I tried to run the Test-HybridConnectivity powershell in the HybridManagement module. It fails with the following errors. I believe it is an issue with TLS 1.2 so I have tried using the command " [Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12" from https://windowstechpro.com/invoke-webrequest-the-underlying-connection-was-closed-an-unexpected-error-occurred-on-a-send/ article but have the same error. I tested on a standard 2012 R2 server and it also fails at first but that command makes it succeed. I also tried setting the registry keys in SCHANNEL\Protocols\TLS 1.2\Server and Client and restarting. There are several clients that I will be migrating this way and all of them fail the test script.

[PS] C:\Windows\system32>Import-Module C:\Scripts\HybridManagement.psm1 [PS] C:\Windows\system32>Test-HybridConnectivity -testO365Endpoints Testing connection to mscrl.microsoft.com on port 80 Testing connection to crl.microsoft.com on port 80 Testing connection to ocsp.msocsp.com on port 80 Testing connection to http://www.microsoft.com on port 80 Testing connection to login.windows.net on port 443 WARNING: Ping to login.windows.net failed -- Status: TimedOut Testing connection to login.microsoftonline.com on port 443 WARNING: Ping to login.microsoftonline.com failed -- Status: TimedOut Testing connection to outlook.office.com on port 443 Performing GET on https://outlook.office.com:443 Testing connection to outlook.office365.com on port 443 Performing GET on https://outlook.office365.com:443 Testing connection to nexus.microsoftonline-p.com on port 443 WARNING: Ping to nexus.microsoftonline-p.com failed -- Status: TimedOut Performing GET on https://nexus.microsoftonline-p.com:443 Invoke-WebRequest : The underlying connection was closed: An unexpected error occurred on a send. At C:\Scripts\HybridManagement.psm1:196 char:19 + $result = Invoke-WebRequest -Method Get -Uri $uri + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + CategoryInfo : InvalidOperation: (System.Net.HttpWebRequest:HttpWebRequest) [Invoke-WebRequest], WebExc eption + FullyQualifiedErrorId : WebCmdletWebResponseException,Microsoft.PowerShell.Commands.InvokeWebRequestCommand