Character set 'utf8mb4' is not a compiled character set and is not specified in the '/usr/share/mysql/charsets/Index.xml' file
I've found a fix for this, which was related to the package php71w-mysqlnd.x86_64 / php71w-mysql.x86_64

My local machine had php71w-mysqlnd.x86_64 installed whereas the live server had php71w-mysql.x86_64

After running the following two commands, it's now working

yum erase php71w-mysql.x86_64
yum install php71w-mysqlnd.x86_64

service httpd restart


Ref: https://stackoverflow.com/a/38006719/871150