Is there a way to go back to OS3?

[Bennor]

Use the forum search feature and search both this subforum and the OS5 subforum. There are a number of discussions on rolling back to OS3.

For example.

How to revert back to OS3 from OS5 for MyCloud Gen2
https://community.wd.com/t/how-to-revert-back-to-os3-from-os5-for-mycloud-gen2/266322