Affected version: 1.6.73-j
The bug
The new launcher is downloaded you click on parts of the launcher other than the underlined "using the new launcher" text. This is pretty confusing because the message at the top of the screen implies that the new launcher is only downloaded when you click on the underlined words.
How to reproduce
Download the "Linux / Other" launcher from https://minecraft.net/en-us/download/alternative
Start the launcher (this will create files in the
%appdata%\.minecraft
folder you might want to remove afterwards)Click next to the "Play" button or on the not underlined part of the message
→ The new launcher is downloaded
Duplicates MCL-3408