Oops… there was a problem during the request after upgrade

Just upgraded to the new beta 2.5 and now Piwik has stopped working properly. Firstly. I get “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 contact your Piwik administrator for assistance.” when I click on any site and also from the dashboard, the evolution graph is showing a missing image.

Here’s the error from the log file:
Cannot use Piwik\Visualization\Config as Config because the name is already in use in /var/www/html/piwik/plugins/CoreVisualizations/Visualizations/HtmlTable/Goals.php on line 16

Piwik has been working great for over 2 years but this new beta broke something.

Anyone know how to solve this?



To fix delete:
as reported at Fatal error: Cannot use Piwik\Visualization\Config as Config · Issue #5905 · matomo-org/matomo · GitHub

I have this problem with one of the sites. It shows up in Dashboard for Visitors in Real-time widget only. I run 2.5.0 and there’s no goal.php.

What else could be a problem?