First of all, since I can't log in to the launcher, I can't check out what version it is in, so I just put the latest version in the list (I am using the beta version that came out on the 14th June 2019).
So, today I was launching the launcher and it must have had another instance initiated at the same time, although I could not see it, because I was put into the launch screen. To my surprise, I can no longer log in to my account and play! It gets stuck on the loading with the 4 squares animation...
I've tried closing and opening the launcher many times and the problem persists...
Don't know if this is a bug or just a problem of mine but I feel like I should report it anyways.
Duplicate of MCL-11001
(it wasn't there when I started writing the bug report, sorry)