Thank you.I can confirm it: latest Entware Transmission 4.0.3-2 crashes and the only fix is to set
in /opt/etc/transmission/settings.jsonCode:"dht-enabled": false,
I am pretty sure the problem is in libdht. Hope it will be updated in a near time.
That solved my problem. A day lost is a problem solved.
Have AC68U with 386.11.
Client on phone and web interface worked instantly, on the desktop I have to delete profiles and make new one.