- Plesk for Windows
Is it possible to downgrade MySQL 5.6 to 5.5 on Windows?
It is strongly not recommended to perform a downgrade on a live server. MySQL 5.5 can be installed on the same server where MySQL 5.6 already exists.
Once MySQL 5.5 is installed and configured, connect it to Plesk using instructions from the following article: How to add additional MySQL server in Plesk?