updating edit css is effecting main nav menu

Hello, I was recently having trouble discovering what was causing my sub menu items to not appear any longer in my drop down menu boxes.

Somebody (some support guy) disabled half my plugins without telling me anything and it was back up.

One by one a activated the plugins and check the menu on the homepage. It worked fine. All the plugins were reactivated, jetpack and WPMUDEV reactivated, and it was working fine.

Then I noticed my button wasn't changing colors on hover and checked the

>Appearance > Edit CSS

The code was still there. As soon as I clicked "Save Stylesheet" my menu is now no longer working right.