Media Library broken after 4.9.6.2 update

New to wordpress here. I was recently granted access to my company’s wordpress ‘newsrooom’ site. My first thought was to update everything- plugins, themes, and WordPress itself (version 3 to version 4). Five minutes later I received a complaint from a coworker that the Media Library had stopped working.

I started googling the issue and while others online shared a similar problem, no one had a good solution. I deactivated all the plugins without making any difference. Changing things beyond that is beyond my scope of knowledge and I need to tread with care. Any suggestions?

The Problem – Selecting ‘Media Library’ from the left side menu navigates to a new page with no options and no media. The ‘add new’ button is still there, but does nothing. Trying to add media to a page also does nothing.

Please help. Thanks!