esmi on "New 4.5 version broke my page completely"

After updating WordPress on my site to a version 4.5 it erased my frontpage completely and all the connections between Menus, Categories and Products. Database still remained. Luckily I make backups of entire page every day and was able to restore it back to version 4.4.2. and its working. Nothing like this has ever happened with any of the updates before and I've been using WordPress for 4 years. Can you explain that? How should I go further?

What theme are you using? What plugins?

Can you explain that?

It can frequently be attributed to a plugin or theme that is no longer compatible with the most recent version of WordPress. Sometimes a simple theme or plugin update solves the problem. The hard part can be identifying exactly what's causing the issue. Some related info that might be of help: https://wordpress.org/support/topic/read-this-first-wordpress-45-master-list?replies=7