ClickHeat doesn't work

Hello,

I installed and activate this ClickHeat plugin.

If i read the installation, then there must shows a link to a JS file, but i can’t see and find a JS file.

If i look in the Piwik DashBoard, the ClickHeat link is showing, but this shows the following error:
Error: Call to a member function read() on boolean

I follow also this topic, but with no luck: https://forum.matomo.org/t/heat-map/15113/7

My wbesites and the Piwik installation works with SSL.
Piwik version: 2.17.1