I'm having the same problem; when I attempt to print a document to PDF I get the message "Error printing on PDF24" and "The printer couldn't print <my document name here>".
I'm using Windows 10 Pro version 1909 OS build 18363.1016 and I too suspect that this is due to a Windows update, which in my case happened yesterday, the same day I started having this problem.
I installed the update and it fixed the error. However, I have the printer set to automatically save files to a folder. Now sometimes it prints to the folder, but other times the PDF24 assistant pops up requiring me to manually save the PDF.
I am also experiencing Printing problem when using PDF24 Creator with Win 10.
However this issue is not seen with Windows Server 2012/2016. Can you kindly suggest if Windows Server 2012/2016 are also impacted and if it is necessary to upgrade for Windows Server too. I don't wish to upgrade tool on server(s) if it is not broken.
I just experienced this issue. I have installed 9.2 but the issue did not go away. Rolling back update KB4580980 seems to have resolved the issue for me. Can you please confirm if there will be a fix for this because at the moment we have paused some updates that we would prefer be applied.