We have just released a hotfix to Skype 5.1 for Mac. With this hotfix we are resolving a startup crash for Mac users who were affected by yesterday's Skype issues.
This update is required to fix a corruption that occurred in a small percentage of users' systems, resulting in some of our community not being able to sign in to Skype. If you have already manually fixed the issue by deleting Skype's configuration file, shared.xml, then the hotfix is not required.
Before downloading you need to ensure that no Skype processes are left running before installing this update, so please be sure to quit your existing Skype application, restart your computer, then begin performing the download.
Start downloading it now.