Troubleshooting HTTP Service Certificate Issue with Plexus Upload Printer

When setting up a new Plexus Upload Printer on recent versions of Windows client (not server), you may encounter the following error:

Error Plexus Upload Printer: An error occurred while making the HTTP request to https://client.plexus.cloud/svc/Interface.svc. This could be due to the fact that the server certificate is not configured properly with HTTP.SYS in the HTTPS case. This could also be caused by a mismatch of the security binding between the client and the server.

This issue is caused by a the fact that the virtual printer and end point will negotiate a secure TLS connection, but various client versions of Windows allow any level of security while Amazon infrastructure requires a more secure version of TLS.

To resolve this, force Windows to use a secure version of TLS by adding the required registry keys.

Assuming the Plexus Upload Printer is already installed and the virtual printer available, do the following:

1. Find the Plexus Upload Printer and disable SNMP
   • In the Windows Printer settings, open "Ports"and then disable SNMP
   • Save and close the Printer dialog
2. Download the registry file attached to this ticket
3. Move the downloaded file to the host computer's desktop and import the Registry keys
   
   • To import, just double click the file (this will import the Registry keys to force the TLS settings)
4. Restart the Windows machine

More information can be found at the following links:

• Transport Layer Security (TLS) best practices with the .NET Framework - .NET Framework | Microsoft Learn
• How to enable Transport Layer Security (TLS) 1.2 on clients - Configuration Manager | Microsoft Learn
• Disable SNMP Status Over the Standard TCP/IP Port (xerox.com)

The attached registry file's contents are as follows:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\WinHttp]      
"DefaultSecureProtocols" = dword:00000AA0

[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Internet Settings\WinHttp] 
"DefaultSecureProtocols" = dword:0000AA0

[HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Microsoft\.NETFramework\v2.0.50727]
"SystemDefaultTlsVersions"=dword:00000001
"SchUseStrongCrypto"=dword:00000001

[HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Microsoft\.NETFramework\v4.0.30319]
"SystemDefaultTlsVersions"=dword:00000001
"SchUseStrongCrypto"=dword:00000001

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\.NETFramework\v2.0.50727]
"SystemDefaultTlsVersions"=dword:00000001
"SchUseStrongCrypto"=dword:00000001

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\.NETFramework\v4.0.30319]
"SystemDefaultTlsVersions"=dword:00000001
"SchUseStrongCrypto"=dword:00000001