In the Access Point hosted in IIS, after following the procedures described at http://help.qlik.com/en-US/nprinting/17.2/Content/On-Demand/Intro-On-Demand.htm
and article 000025887, On Demand button is still missing in the Access Point tool bar. Upon opening a qvw document from the Access Point, browser developer tool shows error GET http://<server>/QvAjaxZfc/htc/addons/config.json 404 (Not Found)
Similar to article 000025887, the issue was caused because JSON and TTF have not been added to supported MIME types of the web server (in this case IIS)
This is a QlikView bug which fails to add these required mime types when QlikView is upgraded. The mime types must be added manually.
This known bug as mentioned in the NPrinting server release notes under "Known Limitations"
Add the JSON and TTF as MIME types in IIS. This can be done by:
1. Open IIS manager > Default Web Site > MIME Types
2. Look for .json and .ttf MIME types in the list. If such entries are not found, add the following entries:
- Extension: .json ; MIME type: application/json
- Extension: .ttf ; MIME type: application/x-font-truetype