Problem: Skype Error message when signing in: “Can’t sign in to Skype for Business – There was a problem acquiring a personal certificate required to sign in. If the problem continues, please contact your support team”.
Uninstalling or reinstalling Office 365 software is not going to help you. There are a couple of solutions here.
Solution 1 Open Skype for Business login window and click on “delete my sign-in info”.