Hi, I'm trying play 1.6.4 but I don't have game sound with the new launcher, I tried with the old one and It works. I hope you can fix this.
PSDT: The Game icon in 1.6.4 is bug
More specifically, sound works fine in the Java launcher version 1.6.73-j, but fails in the native launcher. This seems to be an issue for versions using the "legacy" asset index; versions after that (staring with 1.7.3) launch correctly.
More context for this bug, it looks like the new launcher isn't unpacking the assets into assets/virtual/legacy. I re-downloaded the old launcher, launched the game so that the assets are loaded, then switched back to the new launcher and everything worked. Attempting to launch before from the new launcher created the assets/virtual/legacy folder, but the folder itself was empty.