You have a valid office 365 subscription yet a user complains they cannot create a skype meeting request. You can also tell that when logging in as the user and clicking on the ‘change user’ icon top right that there is no green bar or to sign in to IM. You have waited 24 hours for the service to fully activate – if so, go to Exchange admin and check that the user has an email address
Go to admin centres
Go to mailboxes
Double click the user and select ’email address’ in the window that opens
Check to see if a SIP type entry exists for the user – if not go to add (plus sign), click custom and enter SIP and in the email address field enter the users primary email address
Wait some time for the service to fix itself and try again! For me it took about 1 hour but I was told it could take up to 24 hours to take effect.