Thanks for reaching out on the Wowza Community Forum. The error is an internal error encountered while shutting down the stream. There is an imposed wait time to allow the stream to shutdown.
This is likely occurring because the existing stream name is attempting to be published before the existing stream has properly shut down.
Are you by chance trying to to implement a Many-to-Many workflow? Per our WebRTC workflow documentation, WSE supports few-to-many. To accomplish this, each publisher will need to use their own stream name.
Based on the above are publisher’s using the same stream name for multiple publishing clients at the same time?