Fax reception not working

[ifuser]

Hello everybody,

We use version v11.0.28976.849 SP.4B

Unfortunately, our virtual fax server has not been working for a long time. In the settings I have changed nothing.

When I call under our fax number, the pips sound comes.
When we receive a fax the sender gets an error message "Error during fax transmission"..

Unfortunately, I do not know how I can fix the problem and would be very glad if you can support me in the forum.

Attached you can find the log file

Thanks in advance.