I recently downgraded mysql from 8.0 to 5.7. The downgrade worked fine but somehow today after server shutdown, mysql wont start and below are the errors from : /var/log/mysql/error.log:
[ERROR] Fatal error: Can't open and lock privilege tables: Table 'mysql.columns_priv'
doesn't exist
2021-01-06T13:28:45.064432Z 0 [ERROR] Fatal: can't initialize grant subsystem - 'Table
'mysql.columns_priv' doesn't exist'
2021-01-06T13:28:45.064442Z 0 [ERROR] Fatal error: Failed to initialize ACL/grant/time zones
structures or failed to remove temporary table files.
2021-01-06T13:28:45.064498Z 0 [ERROR] Aborting
2021-01-06T13:28:45.065865Z 0 [Note] Binlog end
Working in ubuntu server 18.04