Accessing phpMyAdmin from an account's cPanel results in:
phpMyAdmin - Error
Error during session start; please check your PHP and/or webserver log file and configure your PHP installation properly. Also ensure that cookies are enabled in your browser.
session_start(): open(SESSION_FILE, O_RDWR) failed: No such file or directory (2)
session_start(): Failed to read session data: files (path: )
This issue is caused by the cPanel account's tmp directory not existing.
Manually create the missing tmp directory with the proper ownership by running the following commands:
chown USER.USER /home/USER/tmp
replacing USER with the cPanel account's username.