How to restore version 12 backup

I want to restore version 12 cloud backup how to restore in local bench version 12 it local version 12 restor time come error ERROR 2006 (HY000) at line 346: MySQL server has gone away
Database not installed, this can due to lack of permission, or that the database name exists.
Check your mysql root password, or use --force to reinstall and check backend through table so only come 5 table not 819 table how to restore backup successfully