Piwik couldn't write to some directories (running as user 'nobody')

Just installed, I get “Piwik couldn’t write to some directories (running as user ‘nobody’).”

I see this asked a few times in this forum, but none of the suggestions are working for me:

I upgraded the server:

cPanel Version 60.0 (build 35)
Apache Version 2.4.25
PHP Version 5.6.30
MySQL Version 10.0.29-MariaDB

All directories are 777.

I do not have SELINUX

I rebooted the server.

What now?

FYI, I use WHM and CPanel.

EDIT: After upgrading to ApacheEasy 4, I get a Server error

EDIT 2: I deleted the entire directory, and uploaded it from scratch. Now I get just a page with just a logo, otherwise it is blank.

4 hours of work and counting: this is really annoying

Solved it by deleting all the Piwik files from the server, and reinstalling them.