I have Piwik installed on my server but since three days it doesn’t track my users anymore. And I am 100% positive that there are visitors. Before it worked flawless for a few weeks and nothing has changed in the latest weeks.
Ok looks like GeoIP that created a problem. What I did to fix it.
Remove the archive tables
Disable GeoIP
Enable GeoIP
And run GeoIP script to fix the old data