Yesterday I upgraded from 2.16.1 to 2.16.2
Mostly it works fine but some widgets in the dashboard show 'Oops… there was a problem during the request […]'
In the apache logfiles there is a
PHP Fatal error: Cannot redeclare class Piwik\\Plugins\\CoreVisualizations\\Visualizations\\HtmlTable in /var/www/piwik/plugins/CoreVisualizations/Visualizations/HtmlTable.php on line 23, referer: http://piwik.example.com/index.php?module=CoreHome&action=index&idSite=1&period=range&date=last30
or another widget:
[Fri Aug 05 19:22:03.828679 2016] [:error] [pid 30782] [client 192.168.5.2:8087] PHP Fatal error: Cannot redeclare class Piwik\\Plugins\\VisitTime\\API in /var/www/piwik/plugins/VisitTime/API.php on line 0, referer: http://piwik.example.com/index.php?module=CoreHome&action=index&idSite=1&period=range&date=last30
The strange part it: it does not always happen. Usually only a few widgets show the problems. Sometimes a refresh of the page will show all widgets properly, or other widgets show an error.
Just to be sure I later removed the entire piwik folder on the webserver en unzipped a fresh copy. After replacing the config.ini.php the problem was still the same.
I restarted Apache but that did not help either.