[trinity-users] no TDE on Mageia 7

Looking in journal and Xorg.0.log I see no clues. X starts, but startx just starts X and exits. Trinity-tdm is installed, but no other *dm, and I see no evidence of its configuration in systemctl list-unit-files or systemctl list-units. /var/log/tdm.log was last written over a year ago. Trinity tries to start using startx /opt/trinity/bin/starttde, but a popup comes twice, then X exits:

"There was an error setting up inter-process communications for TDE. The messag returned by the system was:

Could not read network connection list. /root/.DCOPserver_hp945_0

Please check that the "dcopserver" program is running!"

startx icewm works.

How does one do that, and why isn't there a TDM running?