Error Message 'Create Skype meeting failed. Please make sure that Skype for Business is running and signed-in and try again

Hi,

I need assistance,

when users are trying to create a Skype meeting it fails with the error message "Error Message 'Create Skype meeting failed. Please make sure that Skype for Business is running and signed-in and try again

I am running;

Windows 8.1

Office 2013 with Skype for Business. (We dont have Lync)

Please any assistance will be appreciated.

Thanks,

Hillary.