I don't think you followed my instructions, so let me see if I can make it clearer:
1. Start the MySQL server using your original configuration file.
2. Once the server is running, log in to the server using the mysql client. Then change the SQL mode from there using
SET @@sql_mode = '...'
(replace the
... with your desired SQL mode or modes). You'll probably want to do this as the MySQL root user, so that the mode is enforced for all users.
This may not work as you'd like, but it
might get you up & running temporarily, for now.
The proper solution is to make your applications compliant with strict mode.
Strict mode became the default in MySQL 5.7, that remains the case in MySQL 8.0, and I am at least 99% sure that this is never, ever going to change in future versions. The fact that we ever supported anything other than strict mode as the default was a serious mistake, which we've now rectified.
(Note to Peter B: Feel free to step in here and preach a sermon on data integrity. ;-) )
cheers
Jon Stephens
MySQL Documentation Team @ Oracle
MySQL Dev Zone
MySQL Server Documentation
Oracle