After updating to Piwik 2.6.1 I am now getting this on the Dashboard:
Oops… there was a problem during the request. Maybe the server had a temporary issue, or maybe you requested a report with too much data. Please try again. If this error occurs repeatedly please %scontact your Piwik administrator%s for assistance.
What is going on, seems like all of these updates is breaking everything. Tracking over 300 sites and now the whole thing is down!