MySQL 5.7 downgrade to 5.5

[TarasS]

I've tried to downgrade MySQL 5.7 to 5.5.
I do not have backup of Plesk users and databases for MySQL 5.5.
I can't restore psa database from backups made for MySQL 5.7 because of errors.

Can I reinstall Plesk 12 with empty database to use it on installed MySQL server 5.5?

 

[TarasS]

Yes, it is possible. I did it.

Lessons I've learned:
1. Make backups.
2. Verify your backups are good.
3. Stay calm even if everything seems to be broken for ever.
4. Ask questions if you can't find answers by yourself.

Related forum post: https://talk.plesk.com/threads/plesk-12-db-error-zend_db_adapter_exception.333081

KB I've used to fix found problems:
http://kb.odin.com/118671
http://kb.odin.com/en/124787
http://kb.odin.com/en/119283
http://kb.odin.com/en/122078

@UFHH01, thank you for your help and support. It was very helpful.