See report in the forum: http://forum.piwik.org/read.php?2,109382
The web cron stops completing successfully because of a htaccess file.
Maybe because it does not contain the Allow from all or so that needs to be added for the new apache? maybe we have to re-write the htaccess files on upgrade to 2.1.
In 79bf737f8a0d112015560194efb990dc5eaa6ad4: Fixes #4508 New rules at installation will allow
I stumpled upon this bug just now.
I deleted the .htaccess and ran archive.php in my browser. After running it several times all archiving was done and suddenly there were Error 403 again after I opened the archive.php again in my browser. The .htaccess was also newly generated.
Maybe this helps a bit.
After deleting the .htaccess again the archive script worked fine.
I'm on v2.1.
please can you try with 2.1.1 Beta? this bug was fixed in the beta. Maybe my fix is not correct though, so I would like to hear from you if you can test beta and try again! thanks