After a lot of struggle this was my solution;
It seems a static ip in the 192.168.1.x range is restricted so I changed the ip address of my isp router to 192.168.13.x.
Powered off my pfsense1100 booted with usb (only the righter slot works) and pressed the [y] button a couple of times to prevent autoboot. Then I started the ‘recovery’ instead of ‘install’. And in the recovery I only opened the shell to ping a website and confirmed that my internetconnection was working. Then I typed exit to start with the install. And everything worked instantly.
During the install you get at 3 moments the feeling that everything is stuck. Especially during the last stage, -the real install- just wait for like 10 minutes.