The request was canceled while queueing, the current CefSharp worker number is 1

[Filippo_Nicolussi_P]

Export to PDF or Image of objects or sheets not working on Qlik Sense Enterprise Starting from version  November 2019. 

Checking C:\ProgramData\Qlik\sense\Log\Printing\Trace\[hostname]_System_Prinintg_CefSharp.txt the error reported is: 

[GUID], The wait has timed out. Task status: WaitingForActivation.The request was canceled while queueing, the current CefSharp worker number is 1. 

Environment:

Qlik Sense Enterprise on Windows 

From November 2019 the number of workers is limited to 75% of logical processors present on the machine.

The minimum number of workers required for a Queue is 2, in case 75% of logical processors results in one worker 1 Export will not work.
 
  

Resolution:

Assign to the Virtual Machine at least 4 logical CPU  as per Help. See the System requirements for your version.