1. You need to be on NPrinting 17.2.2 or above to use QlikView Server 12.10 SR1
2. I suggest you go through and follow the instructions in the last video on this page: https://help.qlik.com/en-US/nprinting/17.2/Content/Videos/Intro-Videos.htm
HTH - Daniel.
From Qlik Support (worked for me) :
Go to the QMC, System tab > Setup and click on "QlikView Web Servers" in the tree. Then click on the Web tab to the right
Scroll down the mime types list and see that .JSON and .TTF types are missing
Add these to the mime types list in the Webserver
Note: This solution is only for Qlikview with a QVWS. If you have IIS as the webserver, use article 000027846 instead to fix the problem.