ubuntu 16.04 lts, installation stopped at "Force UEFI Installation?"

HI all,

I'm trying to install ubuntu 16.04 lts by live usb on my new Crucial 750gb ssd.
I used manual partitioning:
EFI partition 300mb primary beginning,
swap 8gb primary beginning,
/ 30gb primary beginning,
/home 100gb primary beginning.

Installation and Partitioning don't start. The process always stucks at "Force UEFI installation?". Cliking on "Continue" doens't force or close the windows.

This is the text inside the window "Force UEFI installation?":
"This machine's firmware has started the installer in UEFI mode but it looks like there may be existing operating systems already installed using "BIOS compatibility mode". If you continue to install Debian in UEFI mode, it might be difficult to reboot the machine into any BIOS-mode operating systems later.

If you wish to install in UEFI mode and don't care about keeping the ability to boot one of the existing systems, you have the option to force that here. If you wish to keep the option to boot an existing operating system, you should choose NOT to force UEFI installation here.")

I only have a new empty crucial 750 ssd and a sandisk ubuntu 16.04 lts live usb. No other os installed.