My launcher updated to the new 2.x launcher
It did not launch with a directory path on another computer on the network

The game directory is invalid or inaccessible.
Error details: The specified path is invalid
Filename on disk: Tester
Path: \\COMPUTER-PC\Public\Minecraft\Tester
Exists: directory

Minecraft was supposed to launch with the directory specified, but the game did not launch, specified path is invalid

To replicate, create a profile with the directory path set to a determined folder on a connected computer on the network, allowing you to play your worlds on any computer on the network without coping them back and forth, as long the computer is on, and is awake.