Qlik NPrinting Qlik Sense Visualization images fail to render export generate or preview

[Frank_S]

Qlik Sense Visualization Images fail to render, export, generate, or preview in Qlik NPrinting Designer or Qlik NPrinting Web Console publish tasks.

Environment:

• All supported Qlik NPrinting versions

Before proceeding with the solution:

1. Restart all Qlik Sense services
2. Restart all Qlik NPrinting services
3. Retest

Resolution

The issue may have different root causes, each with its own solution. Begin implementing the solutions from the top down.

Verify and update the Qlik NPrinting Report and reload the Qlik NPrinting connection

1. Click the Entity Checker button in the Qlik NPrinting Template editor and retest
2. This will ensure that the object (s) are valid (older versions of NPrinting may not include the 'Entity checker' object).
3. Right-click on each table object and select Update from the context menu to update tables changed in the source QVW or QVF.
4. Save and close the report
5. Reload the NPrinting Connection
6. Open and preview the report

The following steps must be performed on your Qlik NPrinting Server/NPrinting Engine Computers.

Disable IE Enhanced Security on the NPrinting Server:

See Microsoft Internet Explorer Enhanced Security Configuration is blocking QV.exe (QlikView) and report....

Update Intranet Security settings:

Log on to the Qlik NPrinting server as the Qlik NPrinting service account and open Internet Explorer. Alternatively, launch Internet Explorer as the Qlik NPrinting scheduler service account. 

Then: 

1. Go to Internet Options
2. Switch to Intranet Security Settings
3. Go to Sites and open Advanced
4. In the Add this website to zone field, insert the FQDN address path of the Qlik Sense virtual proxy server.
   
   Use the central proxy address of your Qlik Sense deployment here as well as in your NPrinting connections proxy address path. 
   
   Insert both as shown below if applicable:
   
   
   • Example with computer name: https://myqliksenseserver.domain.com
   • Example with alias name: https://myaliasqliksenseaddr.domain.com
     
     Reference: Qlik NPrinting will not read Qlik Sense certificates. 

Note: 

• The above steps must be done while logged on as the NPrinting Scheduler Service domain account for these settings to take effect across the enterprise.
• The Qlik NPrinting and Qlik Sense servers and the domain user account(s) running the Qlik NPrinting services must all be members of the same domain.

Enable increased timeout values

On the renderer.config file to as high as 300 secs. See Solution 4 in Advanced troubleshooting of the GRPC and or CEF Errors in Qlik NPrinting.

Verify that you have disabled IE Enhanced Security on your Qlik NPrinting server

See Microsoft Internet Explorer Enhanced Security Configuration is blocking QV.exe (QlikView) and report....

Check to ensure that the NPrinting server and Qlik Sense server are using the same cryptography.

If the Qlik NPrinting Windows server system logs are showing many SChannel errors, this may indicate the Qlik NPrinting server cryptography is not aligned with the Qlik Sense server

To resolve this, as per Qlik NPrinting proxy cipher suites, you may either:

• Manually configure the supported cryptography on the Qlik NPrinting Server to ensure it matches your Qlik Sense server crypto settings as per the link above
• Use IISCrypto (third-party software) and the predefined Best Practices option to set your crypto.

Note:

• If you are hardening your Qlik Sense server, be sure that you do not remove required crypto needed to communicate with the Qlik NPrinting server.
• Each Qlik Sense node should have the required NPrinting crypto configuration in common

Content Security Policy settings in Qlik Sense can cause images in NPrinting to fail

The use of CSP (Content Security Policy) may be the root cause if none of the above is working. In this case, you may simply remove the additional headers in Qlik Sense or add the required additional headers as needed.

Please work with your IT security team to determine the correct headers for your specific environment. See How to add additional response headers in Qlik Sense.

Qlik Sense theme or extension causes rendering issues:

In case you find the following in your Qlik NPrinting logs:

qlikPrintingService.renderOnline("9f6e759f-xxxx-xxxx-xxxx-xxxxxx9a8c18","np17-6233xxxx-7ef8-4233-bd60-xxxxxxxxxxxxxx","object","zHxxMg","render",{"jsTimeoutMsec":"60000","theme":"MyTheme360_xyz"})

Reload the Qlik Sense app to apply the theme (see Connecting to Qlik Sense apps on a Qlik Sense server). If your theme is a custom theme or the theme simply is not working for you, switch to classic or other built-in themes in your Qlik Sense app.

Your custom theme or custom extension used may have issues blocking rendering. ie: contains links to external sites. Check your theme for this and other blocking issues.

Should none of the above help resolve the issue, collect a HAR file while the issue is seen, then contact Qlik Support so we can help you identify the root cause. Always verify all the above first.

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• Advanced troubleshooting of the GRPC and or CEF Errors in Qlik NPrinting