Skype stuck on "Signing in" window After upgrading OSX to Yosemite and Skype to 7.7 (335), Skype gets stuck on "Signing in..." when starting. 

It does sign in, as Contacts > Add Contact forces the main window to open, but "Signing in..." never goes away.

Already tried, but didn't work:


Signing out, quitting ("Signing in..." stays even when signed out), then signing back in.
Everything on the Skype support page for Why can't I sign in to Skype for Mac OS X?.
Removing ~/Library/Application Support/Skype.
Reinstalling Skype


I'm using my Microsoft ID to sign in.

Any clues?



Following the @Buscar advice I used nettop in terminal to monitor Skype connections.

After quitting Skype, I see 3 connections still there about 20 seconds after quitting. Two of them use port 443 (status LastAck and FinWait1), the other is on a high port (12k+), status FinWait1. Last one to go away is to blu403-m.hotmail.com:443 with status FinWait1.
The following procedure seems to have solved the problem:


Sign out from Skype
Quit Skype and wait until all connections listed in nettop are cleared
Open Skype
Choose "Sign in with a different account" from the Microsoft ID login screen.
Try to sign in with Skype Name (but fail, since I can't do that anymore after I linked my Skype account to my MS account).
Go back and sign in with my Microsoft ID.


The "Signing in..." window was displayed for a few seconds, then the home window opened normally. Problem solved. I'm guessing steps 4-6 solved the issue, but I have no idea why.