In the beginning I had 3.042.040, I was thinking this was the last version.
So when I have realized my error, I have downloaded 3.043.011
After that It was impossible to open Mach 3 with Machstdmill . I got the message my version was not correct.
I make a lot of try, uninstall mach3 3.042.040 and 3.043.11. Re-install 3.043.011 and re-install Machstdmill. I always got the same message, my version is too older