“The mbstring PHP extension was not found and you seem to be using a multibyte charset. Without the mbstring extension phpMyAdmin is unable to split strings correctly and it may result in unexpected results”

and

“Cannot load mycrypt extension. Please check you PHP configuration”

You are not alone, you can solve the problems with the followings steps.

mbstring

New linux repo has the mbstring removed by default, just install it back.

#yum install php-mbstring

mycrypt

Install libmcrypt and php-mcrypt

#yum install libmcrypt
#yum –enablerepo=centosplus install php-mcrypt

Restart your apache / httpd, the warnings should have gone now.