Ulf,
Please post all your error messages/logs. Otherwise we can only guess which step you are stuck on.
If you are talking about the infinite loop at the end of program load, according to the team that design the chip and emulation script, it is because the program you are trying to load doesn't setup the reset vectors properly. This cause an annoying infinite loop/crash and they will work to make this better in the future. Your code should still be written to flash successfully at this point.
Victor