I have upgraded to piwik 1.6 and geoip plugin to v0.18 about an hour ago.
I had the same problem with previous versions.
I turned display_errors = On in php.ini but still no error message, maybe I got to wait a lot longer for apache to refresh, but still something is wrong there.
Good news: GeoIP is now integrated in Piwik, enabling Accurate Visitors Geolocation in your Analytics reports. To enable GeoIP go to the Settings > Geolocation admin page, and follow the short instructions.
Yeap, thanks matt and all the team, it works great as integrated, already removed the old stuff.
The link you gave is “The page isn’t redirecting properly” but I guess it is about geolite city ? this is the one I use in piwik.
By the way, the worldmap I think still shows only countries right ?