Symptoms
In a Microsoft Skype for Business Server 2015 environment, you set the Call Action feature to Forward to another queue or Forward to SIP address for a response group queue. When a user calls this response group (RGS), the call is stuck in the queue until it's hung up and not forwarded to the queue or SIP address as configured.
Resolution
To fix this issue, install the January 2019 cumulative update 6.0.9319.537 for Skype for Business Server 2015, Response Group Service.
