ERROR 3021 (HY000): Unknown error 3021 [How to Solve]

An error is reported when implementing MySQL master-slave replication configuration, as shown in the figure:


Reason: it is not allowed to change when starting MySQL master-slave replication
Solution: first turn off MySQL master-slave replication, then refresh, then make changes, and then turn on MySQL master-slave replication
① turn off MySQL master-slave replication

stop slave;

② Refresh

flush privileges;

③ Enable MySQL master-slave replication

start slave;

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