If you change/copy the profile to point to a folder to which cannot be created, then the launcher fails to create the game directory as expected, but this locks the launcher into a launch limbo with only way to fix is by restarting.

Replicated by

• Created launcher_profile.json on one machine with account name "Laptop"
• Copied .minecraft folder to my new account named "Joshua"
• Attempted to launch game without fixing path