javascript not being written into footer

Your theme may missing the $closure variable.

I have the same problem on my site, http://peterdedecker.eu. I guess the problem arises because the piwik webinterface can be found at https://stats.ginsys.net/ instead of peterdedecker.eu/piwik. The only configuration parameter I could find, is the user auth token, nothing else. I also couldn't find a place to define what user roles should be tracked. Am I doing something wrong?

Until the piwik module has verified the link to piwik server files successfully - it's not working. GA is successfully working as I can see - piwik must therefore work, too.

Make sure your server can issue external HTTP requests. There is no need to have piwik in a subdirectory... and this have all nothing to do with auth token. The main settings can be found in Settings > Piwik - the URL is "admin/settings/piwik".

I'm not sure if your invalid SSL cert could cause such issues... try first without SSL, only to see if it works.

OK, thanks, I've found the problem. When I looked on the admin page, I could only find the piwik stats but no page to configure the piwik module (site ID and url). However, a status report now told me I had to configure the piwik module and provided the right url to do so. Do you have any idea why it didn't show up on the admin page?

Now the javascript is written to the footer, thanks!

You need to be user1 or grant the administer piwik permission to your role.