I come back to my post which did not get any answer!
I stopped wrongly CQR while updating the DXCC list.
Since that time CQR log does not want to start.
I get this warning at start:
Press OK to ignore and risk data corruption.
Press Cancel to kill the program.
I tried to re-install it but without success.
I tried to set-up manually the country list, but this also failed.
So I have no log since a few weeks, and I consider turning back to W10 and logger32!!
Thanks for your help.