Did you open an specific page or does it appear on every page? Is everything else working as expected?

And can you go to Administration => Plugins and list the third party plugins? You may also want to clear the cache manually once eg using ./console cache:clear in your Matomo directory (if possible)

@sgiehl everything is working as expected, just a LOT of warnings.

@tsteur the list of third party plugins is:

• AOM (v1.4.4)
• BotTracker (v1.06)
• DeviceFeatureWebGL (v1.0.2)
• ExposureResearchTools (v0.1.9)
• FlagCounter (v3.0.3)
• LanguageToogle (v0.2.0)
• ReferrersManager (v3.0.4)

Running ./console cache:clear showed a different error:

WARNING [2019-10-28 17:51:16] 14230  /var/www/piwik/vendor/doctrine/cache/lib/Doctrine/Common/Cache/RedisCache.php(135): Deprecated - Function Redis::delete() is deprecated - Matomo 3.11.0 - Please report this message in the Matomo forums: https://forum.matomo.org (please do a search first as it might have been reported already)

Caches cleared

Error: error or warning logs detected, exit 1

Going back to php-fpm 7.2+60ubuntu1 seems to solve all the warnings but given CVE-2019-11043 this is a no go.

Could you maybe disable one plugin after another to see when the error cannot be reproduced anymore? Or maybe first disable all of the mentioned plugins to see if it still happens. Just for a short time. That would help.

Ok, I deactivated all of them, and then started activating the plugins one by one and the problem seems to be with:

• AOM (v1.4.4)
• DeviceFeatureWebGL (v1.0.2)
• LanguageToogle (v0.2.0)

The only remaining deprecation warning is:

/var/www/piwik/vendor/doctrine/cache/lib/Doctrine/Common/Cache/RedisCache.php(135): Deprecated - Function Redis::delete() is deprecated - Matomo 3.11.0 - Please report this message in the Matomo forums: https://forum.matomo.org (please do a search first as it might have been reported already)

While using the Redis Cache for queuedtracking:process

Created matomo-org/component-cache#23 @dktcoding and added this to current sprint. A workaround for now be to change in the file /var/www/piwik/vendor/doctrine/cache/lib/Doctrine/Common/Cache/RedisCache.php line 135 the delete to del.

I will otherwise close the issue as it seems to be related with a 3rd party plugin unfortunately. I recommend you create an issue for the other plugin. I would suspect LanguageToggle might not be causing it but one of the other two.