PHPMyAdmin :: Cannot start session without errors - Direct Admin

Check what does it say in your apache error log?

/var/log/http/error_log
/var/log/http/domains/yourdomain.com.error.log

Run this command to make sure that Php works:
php -v

and this command to see a list of compiled modules:
php -m

If these are good and error(s) free, re-install PhpMyAdmin. If none of this worked, re-compile Php and make sure you do not get errors throughout the process.

You need to just ran the command below
#  /usr/local/directadmin/custombuild/build phpmyadmin

This will fix your issue..