Microsoft has planned maintenance for Skype for Business on Tuesday, July 17, 4:00 - 6:00 pm.
During this time, Skype for Business users will experience limited functionality and will be unable to perform actions that change the state of the user (create new group, create new meetings, changing presence). However, messaging/calling and the ability to join previously activated meetings should not be impacted. The expected time of impact will be 60 minutes or less.