I can't login

i have got the same problem in the beta launcher and the settings are not accessible when not logged in so i cannot revert to the current launcher

Same issue here. It started after updating the Minecraft Launcher for MacOS to version 426 (1).

Come on, guys! Search if there are reports that describe your bug before creating a new one! This helps both the moderators of the bug tracker and the developer team find bugs they haven't fixed yet quicker. In this case, this is a duplicate of MC-11001

Press the windows key+R at the same time and type '%appdata%/.minecraft'
In that folder, open the 'launcher_profiles.json' using notepad. At the bottom of the file and change "channel": "beta", to "channel": "release"

@morpheus - How do I edit this same file on MacOS? I can find the file, but I have no way to view and edit the contents.