Error Message

When viewing managed apps an error may be displayed,

• "An unexpected error occurred on a send"
• "An unexpected error occurred on a receive"

This behavior has been observed when Exchange has been configured to utilize a more secured protocol (TLS 1.2).

This is a Windows Server component used to provide identity security checking and authentication to enable secure, private communications through encryption. It relies on the cryptographic protocol in place.

• HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.2
• HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.2\Client 
  • “DisabledByDefault”=dword:00000000
  • “Enabled”=dword:00000001
• HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.2\Server
  • “DisabledByDefault”=dword:00000000
  • “Enabled”=dword:00000001

Warning: Incorrect use of the Windows registry editor may prevent the operating system from functioning properly. Great care should be taken when making changes to a Windows registry. Registry modifications should only be carried-out by persons experienced in the use of the registry editor application. It is recommended that a complete backup of the registry and workstation be made prior to making any registry changes.

WinHTTP provides a high-level server interface to the HTTP/1.1 Internet Protocol that applications and services running on Windows Server can use when establishing secure encrypted HTTPS sessions. Exchange uses it extensively. To ensure that WinHTTP is using TLS 1.2 make sure the following Registry keys are set:

• HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\WinHttp “DefaultSecureProtocols”:dword:00000a80
• HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows\CurrentVersion\Internet Settings\WinHttp “DefaultSecureProtocols”:dword:00000a80

The .NET Framework is a core set of code libraries and runtimes that are used by many Windows Server-based services and Applications, including Exchange Server. It’s essential to ensure that the .NET Framework is using TLS 1.2 to encrypt and secure the many API points it provides and uses to communicate. To do this makes sure the following registry keys are set:

• HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\.NETFramework\v4.0.30319 “SystemDefaultTlsVersions”=dword:00000001
• HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\.NETFramework\v4.0.30319 “SystemDefaultTlsVersions”=dword:00000001

Reboot the Exchange Server(s) once the above registry keys has been applied.

Note: Action Items, Bing Maps are also missing