Resolved Error SPectrum Template

Hello,
After installing trmpalte its working while and after i get in broswer just word Error

and i when i check the error log iget this error below


[14-Dec-2018 18:17:36 UTC] PHP Warning: session_start(): Failed to read session data: user (path: /opt/alt/php72/var/lib/php/session) in /home//public_html/fi/libraries/joomla/session/handler/native.php on line 260

so can you please tell how i can fix this issue

Regards