Maridb Error ' Operation DROP USER failed for

Database version: Mariadb 10.0.12

The main library removes redundant user names because there is no such information from the library causing master-slave failure!

The error message is as follows:
Error ' Operation DROP USER failed for ' username ' @ ' 192.16.% '

Master-Slave error skipping for multi-source replication:

According to MySQL operation mode sql_slave_skip_counter = 1, do not error, but Sql_slave_skip_counter = 1 will not take effect

The multi-source master-Slave Jump error operation is as follows:

SET @ @default_master_connection = ' master_01 ';
SET GLOBAL sql_slave_skip_counter = 1;
STOP SLAVE ' master_01 ' ;
START SLAVE ' master_01 ';

Maridb Error ' Operation DROP USER failed for