Make sure you are signed in at plex.tv/link, then get a fresh code on your TV and enter it exactly as shown while the code screen stays open.
Quick fixes
1
Sign in on the website first
If plex.tv/link shows a sign-in or sign-up page, your session expired. Sign in, and the code entry page appears.
2
Get a new code
Codes are temporary. Go back on the TV and select Sign In again for a fresh code.
3
Keep the TV code screen open
Do not close the app or switch inputs until the TV refreshes.
4
Check each character
Enter all 4 characters exactly. Look closely at similar characters such as 0 and O.
5
Use the same account
Sign in to the same Plex account on the website that you want on the TV.
6
Check your internet connection
Confirm both the TV and your phone or computer are online.
7
Restart or reinstall the app
Close and reopen Plex, restart the TV, or reinstall the app, then link again.