If you can no longer see the Approve / Disapprove option please do the following steps as a workaround.
Approving Channels:
Step 1: Add "?disable_polymer=true" to the end of the URL and it will show up (see below).
Approving Videos:
Step 1: Click on your user account icon in the upper right hand corner.
Step 2: Click on "Settings".
Step 3: Click on "View additional features" towards the middle of the screen.
Step 4: Expand top left hand hamburger menu (see image below).
Step 5: Click "Home".
Step 6: Then find your video again or paste in the URL for the video in the search bar and the approval button should be there as normal.
This is a bug with YouTube that will be fixed very soon we are being told. We apologize for the inconvenience. If you still have issues with this please submit an Esupport ticket.