After upgrade my website from Drupal 7 to Drupal 8 my Piwik stats doesn’t work. I decide to delete all files from piwik dir and reinstall. Now when I’m trying to install Piwik/Matomo I get an error:
403 error - access denied
You do not have access to the website http[:]//xxx/xxx/index.php?action=systemCheck
I’ve search for solution but I did not find anything to help.
Apache Server hasn’t any interesting logs. I suppose that issue might be regarding with .htaccess file, because on webpage domain.com/piwik/ the Matomo instalation is loading without CSS syles. Next instalation’s webpage getting 403 error.
If it’s easily possible for you, I’d recommend you to install Matomo to a subdomain with an extra vHost in Apache. That way Drupal’s .htaccess can’t interfere.