Hi, its me again.
I have a question about the unity prefabs. One guy here at the office told me that the prefabs could get lost or even damaged, after loading all my data with the new version of unity.
Could this really happen?
I like my prefabs really much and i wont create them again after upgrading unity.
thanks 
Backup a project before opening it with a new version. Everything will probably be fine, but of course there’s a chance something will get broken. So yeah, backup.
I advise one more thing : Export the complete project using Go to Assets>Export Packages , later you can easily import directly in the new version of unity…nothing will be lost here
Thank you very much, i’ll give it a try in the next few days.