First of all, I want to thank you for looking into my problem.
Actually I solved the problem:
After multiple installations and uninstallations, I solved this error by replacing the dll in DS 4.20 with a dll that seemed obsolete but which works perfectly on my system.
What I can’t grasp is that with David’s latest dll: dzunrealbridge.dll.v2022.2.18.23 it worked as soon as UE5 was installed.
Then, after the aforementioned crash, it never worked again.
I installed this dll by chance and it works perfectly. I am unable to give the version and the date of this dll because when I open it in notepad, everything is in machine language, therefore unreadable. ( i’am not a programmer)
After having made several tests by creating new projects and having good results, I replaced the dll of Daz by that of David and again import problems.
I replaced it again with that old DS dll and it works again.
The problem is not really solved but maybe with a version 5.0.4 everything will be fine 
Thanks again for your reply.
deltac1