since Serv-U Version 15.4 Event "Over Disk Space" not more triggered ?

since Serv-U 15.4 the Event "Over Disk Space" not more triggered (exceeding the Max Dir Size)

Test Upload a big File with SFTP Client (WinSCP 6.1) to Serv-U Version 15.4.0.147  the Connection closed by Reaching the Max Dir Size Limit with Message

"Received SSH2_MSG_CHANNEL_DATA for nonexistent channel 0".

No Info in Server Log / Domain Log / User Log (with and without enable a logging option in Log File Options)

No defined Event Triggered here (befor Version 15.4 is this functional) on Server / Domain / User Level.

Here a Extract from WinSCP Client Log:

Received SSH2_MSG_CHANNEL_DATA for nonexistent channel 0
Attempt to close connection due to fatal exception:
Received SSH2_MSG_CHANNEL_DATA for nonexistent channel 0
Closing connection.
Fatal error while disposing the SFTP queue.

In the Log Files you have no Chanche to find the Problem Source on Client or Server Site ...

PS: the Event  "Over Disk Space" is not the Event "Over Quota"