NPRINTING ERROR CEF RENDERING EXCEPTION Cipher Issue

[Sonja_Bauernfeind]

Description

• NPrinting reports fail to render when images are included
• Note: NP Engine and NP scheduler may also be in an non functional state

Environment

• Qlik NPrinting 

Resolution

Diagnosis:

• Check for the following error in the following log file "nprinting_engine_cef.log"
• "RabbitMq server is not connected - trying diagnoser queue creation again in 10 seconds".

"Error in connection establishment: net::ERR_CONNECTION_CLOSED"

• Search the windows system event logs for SChannel errors first on the NPrinting Server and NPrinting Engine computers then also on the Qlik Sense server
• If you see either or both of these, please proceed to the resolution below

Solution:

• Engage with the customer or partner IT department
• Ensure TLS 1.2 is enabled on the NPrinting and or Qlik Sense Server. This is a requirement:
  • https://help.qlik.com/en-US/nprinting/Content/NPrinting/DeployingQVNprinting/System-requirements_eng...
  • Platform security: TLS 1.2 must be enabled.

Recommend Using IISCrypto (or customer's own preferred method) to check for TLS 1.2 and enabled or missing ciphers

• https://www.nartac.com/Downloads/IISCrypto/IISCrypto.exe),
• Ensure that these cipher suites below are enabled on NPrinting machines. If they do not appear, then they must be added:

TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
TLS_RSA_WITH_AES_256_GCM_SHA384
TLS_RSA_WITH_AES_128_GCM_SHA256
TLS_RSA_WITH_AES_256_CBC_SHA
TLS_RSA_WITH_AES_128_CBC_SHA

Minimum cipher requirements on the Qlik Sense server machines which NPrinting connects to:

TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA

Cause 

• Minimum Cipher requirements and or TLS requirements are not met for the version of NPrinting current running
• There is NOT at least one common cipher on the NPrinting and Qlik Sense server

Related Information:

• https://help.qlik.com/en-US/nprinting/Content/NPrinting/DeployingQVNprinting/System-requirements_eng...
• https://help.qlik.com/en-US/nprinting/Content/NPrinting/DeployingQVNprinting/TLS-cipher-suites.htm
• https://community.qlik.com/t5/Knowledge-Base/TLS-and-SSL-Support-in-Qlik-Sense-How-to-configure-Qlik...