Post upgrade of QlikView Server, the AccessPoint does not show any document thumbnails. The document count is however shown.
If you open AccessPoint in Chrome and open the browser's developer tools, you can see the images loading:
Cause
This is caused by the %Program Files%\QlikView\Web\index.htm file not being updated in the upgrade process.
Resolution
Option 1:
If you have another QlikView Server environment running the same build version you upgraded to, copy the index.htm from that system.
Option 2:
Rename index.htm and run on a repair on QlikView Server from the Windows Control Panel and Programs and Features.