On demo.piwik.org, I added the "Browser Family" widget to the dashboard, and got the infamous:
Open Flash Chart IO ERROR Loading test data Error <a href='/2032'>#2032</a> This is the URL that I tried to open: ../data-files/bar-groups-with-nulls.txt
This has been showing up a lot in the error.log, so I'm not the only one seeing this problem on the demo:
File does not exist: /WEBROOT/data-files, referer: http://demo.piwik.org/libs/open-flash-chart/open-flash-chart.swf?piwik=0.9
Strange, looks like a 'random bug'? works for me at the moment. Maybe this is caused when the ajax request fails to return data?
Seems reproduceable with IE8. Also getting spurious "is null or not an object" when deleting the flash widget from the dashboard.
I think this was related to #1634. I can't reproduce this locally, so I'm now closing.