When setting up NC on shared hosting logging in goes back to login prompt after first run

When setting up NC on shared hosting logging in goes back to login prompt after first run. I installed using the setup-nextcloud.php script and followed the instructions.

Got this in the log:

03T16:11:50+00:00","remoteAddr":"86.15.116.8","user":"--","app":"PHP","method":"GET","url":"\/cron.php","message":"session_write_close(): open(\/var\/www\/vhosts\/mjhooper.co.uk\/subdomains\/files.mjhooper.co.uk\/session\/sess_051m98vm0h3vbk7v2hpmh06i60, O_RDWR) failed: No such file or directory (2) at \/var\/www\/vhosts\/mjhooper.co.uk\/subdomains\/files.mjhooper.co.uk\/httpdocs\/lib\/private\/Session\/Interna

How do I set the sessions up? What perms do I need?