PUBG's message, "Not authorizing players' platforms" can be frustrating at times and can be an issue from different problems. These problems can be the result of servers being full or files not being validated, here are some ways to fix the error when prompted for players not authorized.
PUBG Not Authorized by Your Platform: How to Fix the Error
For PC, when logging into Steam, users will want to get into their library of games and search for PUBG. Once the game is located in the library, locate the settings and click manage. Options will be prompted on-screen and select properties. A new window will appear, search for local files and select verify the integrity of game files. Steam will update these files that will reauthorize the game for PC users.
For consoles is a different outcome on resolving the issue, these platforms don't have much control to bypass the error on the screen. Uninstalling and installing will not work because the issue is PUBG systems at the time are overloaded during prime time with a high player count; holidays and summer.
Users will have to wait for a while for PUBG servers to adjust and will need a full shut-down of their consoles. A full shutdown will help the consoles reconnect to the servers and bypass the error on the screen once prime time has passed.
For more support, check out PUBG failed authentications.