How to fix the error “Matomo is unable to write to some directories”?

This error can usually be resolved by executing the commands shown in the error message in the Matomo UI, for example:

For the server you use (Apache, Nginx, or Windows), please find the configuration file. See what “user name” the config file runs things as. You can discover this by searching the web server config file for “user” and “group”. In Apache servers, both of the following names are common: www-data or apache.

Then you can change the owner permission on all of your Matomo files, using whichever command below matches your server’s name.

sudo chown -R www-data:www-data /path/to/matomo/*
sudo chown -R apache:apache /path/to/matomo/*

If your server is running CentOS, SELinux or Redhat Enterprise Linux (RHEL), you may be able to fix the issue with the following commands:

chcon -R -t httpd_sys_rw_content_t /path/to/matomo
semanage fcontext -a -t httpd_sys_rw_content_t "/path/to/matomo(/.*)?"

(Replace /path/to/matomo with the path to the Matomo directory)

In case you try the above and are still having problems, here is a longer example, for a server named www-data (the most common name), which might help you also:

sudo chown -R www-data:www-data /var/www/html/matomo # I am assuming www-data is the server's name AND that the path to your matomo directory is /var/www/html/
sudo find /var/www/html/matomo/tmp -type f -exec chmod 644 {} \;
sudo find /var/www/html/matomo/tmp -type d -exec chmod 755 {} \;
sudo find /var/www/html/matomo/tmp/assets -type f -exec chmod 644 {} \;
sudo find /var/www/html/matomo/tmp/assets -type d -exec chmod 755 {} \;
sudo find /var/www/html/matomo/tmp/assets -type f -exec chmod 644 {} \;