DJ-Events, submitting an item in frontend stopt working

DJ-Events, submitting an item in frontend stopt working

Hello,
On my Joomlasite 3.10.5 and DJ-Events 1..4.1 I always had a perfect working option to add DJ-Events items on the frontend.
But now, when I click on the menu-item to add a DJ-events-item I get a
 

500 Layout default_legacy not found

Any ideas?

By the way, when I install DJ-Events Light 1.4.1 it stays 1.4!

Regards,
Rienk