Hi @broros thanks for creating the issue. Most likely this is a server configuration issue. Be good to check the file permissions and that the correct user can write these directories. Does your solution in #15509 (comment) not work anymore?

If PHP tells us a directory is not writable, then more than likely it is actually not writable for PHP. Maybe check what permissions these run.

I don't think you get it... it's not the folder permission. This happens when I change to FastCGI PHP mode Vs FPM

This should not be happening :(

If the problem happens after the change, the php-fpm service might run under a different user than the apache2 does and therefore has no write permission for the tracker folder.
Check your pool-Config for "Unix user/group of processes" and/or check with ps aux | grep php-fpm what user is running fpm.

1. Limit the file systems writes your PHP application needs to do when running in a web context
2. Keep those writes under a limited number of directories (ideally one)
3. Abstract any file system read/writes to a single system which allows you to

• Control the PHP umask when making file system read/writes
• Provide user-friendly error-messaging/experience when you run into a permission problem
• Swap in a different system for reads and writes (everything from transfers/writes via SFTP, or replacing the whole thing with redis)

Off the top of my head — Joomla, WordPress, Drupal, Laravel — they all have (intentionally or not) created platforms that hew to the above.