Je suis tres bien, merci beacoup

Ok, back to the issue. First of all, be careful to don't fall in the following trap:
- you have installed both Assistant (with 3CXPhone 5) and the standalone new 3CXPhone 6. If 3CXPhone 5 is running and you attempt to start 3CXPhone 6, after that the running 3CXPhone will be 5, so check in the About for version, to be sure.
About 3CXPhone 6:
- by setting PrefEx=1 (as you done) then, when clicking Preferences option in the main menu will open a "new", "reshaped" preferences dialog.
- In the NEW preferences dialog, on "Behavior" page, the last checkbox option is "Use assist dialog on attended call transfers". According to your ini file (UseTransferDialog=1) this option should appear as checked. So, unckeck it then press OK and try a transfer - the transfer dialog should no longer appear. Also, as an additional test, reload the configuration file and check if UseTransferDialog=0.
Please tell me if is working.
Regards
vali