An update.

I fixed my issue by:

mysql>DROP DATABASE emoncms;
mysql>drop user ‘emoncms’@‘localhost’;
mysql>flush privileges;
mysql>exit

restart computer

mysql -u root -p
mysql> CREATE DATABASE emoncms DEFAULT CHARACTER SET utf8;
mysql> CREATE USER ‘emoncms’@‘localhost’ IDENTIFIED BY ‘YOUR_SECURE_PASSWORD_HERE’;
mysql> GRANT ALL ON emoncms.* TO ‘emoncms’@‘localhost’;
mysql> flush privileges;
mysql> exit

Now emoncms server is working fine. Thanks