Problem upgrading Zabbix

[akbar415]

I'm tryin to upgrade from 2.4 to 3.0


I'm following this manual.
https://www.zabbix.com/documentation/3.0/manual/installation/upgrade#server_upgrade_process


But I'm getting this error

[Z3005] query failed: [1022] Can't write; duplicate key in table '#sql-447_ab' 
[alter table screen_usrgrp add constraint c_screen_usrgrp_1 foreign key (screenid) references screens (screenid) on delete cascade]

It's mysql database.


Any hint?