There are two places you can check to see if your media player has updated.
Displays page
Step 1
Navigate to the 'Display Settings & Tags' page using the top left navigation
Step 2
Select the display you want to check on the left (you can use the search bar to make finding it easier). Once you see your display is selected on the right, 'Content Update' will be marked with a green dot (updated) or red dot (not updated).
Manage Page
Step 1
Navigate to the manage page using the top left navigation
Step 2
Click 'Status' in the left sidebar and you'll be given the Status Report dialog. It will show you your online and offline media players and will also tell you whether they're updated with a green dot (updated) or red dot (not updated).