Skype For Business Mac We Couldn%27t Sign You In

Issue

Bob had a computer. He could log in and use Skype for Business and he was happy. Steve was hired and management said, “Hey, Bob, you’ve been here a while, we’re going to give you a new computer and give yours to Steve!” Bob is happy to get a new computer and from the start, things look good — he can log in and do his job, but then the.
When trying to use the Skype option in office 365 we get the following message 'We couldn't sign you in. Please try to sign in again or refresh the page.' And this just goes round in a circle. When you click on 'Learn More.' Option it takes you to a support page here.

A valid Skype for Business license muste be assigned in the Office 365 Admin Portal and the latest version of Skype for Business should be installed. Make sure that your computer clock is set to the correct time because Skype uses a timestamp as part of the authentication process. You need a sign-in address and password from an organization that has a Skype for Business or Lync license. If you’re already using Skype for Business on your desktop, then you can sign in with the credentials from your work or school account. How do I reset my password?

A customer is still using Lync Server 2010 and receives the following error when trying to connect to Lync using a Skype for Business 2016 client: “Can’t sign in to Skype for Business: Cannot sign in because the server version is incompatible with Skype for Business. Contact your support team with this information”.

Investigation

Clients running Skype for Business 2015 client can connect successfully. However, the Skype for Business 2015 clients are only able to connect because of the presence of the following registry key (for Office 2015) on their machines:

Key: HKLMSOFTWAREPoliciesMicrosoftOffice15.0Lync
Name: DisableServerCheck
Type: DWORD
Value: 1 (00000001)

Resolution

Add the following registry key for Office 2016. Reboot the client and they will be able to connect to Lync.