Categories/search menu won't show up

Hey Guys,

I’ve tried searching this issue on google, but I mainly found people having trouble with posts showing up, which is not the problem I’m having.

A couple of days ago I made a WP multisite with two blogs identical to each other, one for the people of our branch office (I guess that’s how you call it) and one for the of another branch office.

Somehow sometime in the process we lost our search and categories menu on our blog (If it’s not clear what I’m talking about, which is possible since I don’t know how to call it otherwise, I mean the menu thing on the right side) but the blog I made for the other branch office still has it.
Anyone has an idea how this might’ve happened and how I could solve this problem?

Thanks in advance, your help will be much appreciated!