Problem after the upgrade to 4.0.2 caused a database problem

a couple of days ago I did an automatic update to Matomo 4.0.2. That resulted in a hosed database. This was probably my fault beca<use I did not see that I was supposed to delete some files.
The db is fixed now and I can log back into Matomo (, but I get an error that I don’t understand what I need to do. I attached a screenshot

Thanks for any pointers!


Could you please check the PHP error log or the Matomo log to find out what exact error is happening?

Matomo log was not enabled (now is) and PHP error log I cannot find.

Hi Ferdinand, could you please open the Developer Tools in your browser (F12), refresh the dashboard and make us a screenshot of the requests/their http codes?

But your login screen is already weird - 50% of the time I get an 500 (internal server error) there. Is this a loadbalanced environment / server is too busy / something is cached wrong?

Hi, Peterbo, the WP instance runs fine and fast (before the update on last Saturday). No load balancing and enough resources. I hope the attached screenshot is what you asked for.

Hi Ferdinand, please look for the PHP error log within your hosting environment. That’s the place where the reason for the 500 error will be explained. If you have access to the filesystem on your server, this could be within the vHost of Matomo or in the directory /var/log/. Or, if you have cPanel, Plesk or similar, you can look for the error log there.

That must be some kind of configuration thing, because every second or third time, your login screen is refreshed, theres a message like this: