I took the following steps to get around the issue:
Ran launcher in administrator mode
Created a profile for the 1.16.3 version
Launched the game with the 1.16.3 profile
Closed Minecraft
Switched back to my latest release profile
Launched the game
Was able to join my realms server without the error appearing
Keerarae T`Devick
I took the following steps to get around the issue:
Ran launcher in administrator mode
Created a profile for the 1.16.3 version
Launched the game with the 1.16.3 profile
Closed Minecraft
Switched back to my latest release profile
Launched the game
Was able to join my realms server without the error appearing