Hi Alice,
So, i added the additionnal SDK library, from here, i created a new project :

then i choose my SDK library with my ship :

i used in the tab below every fonction i use for my project : UART, lptmr, GPIO etc... and then i click on finish.
my project is created successfully :

when i debug it, i got no problem.
then time to run it : i go on run configurations and create a new one and let the settings as default :

i also tried with a build configuration on "use active" or "debug", it does not change anything.
and then i run the program :

and there it is, i don't understand why it does that.
But, i tried to flash the program, and it worked. i don't fully understand the difference between those two, but the flash worked.
do you have any ideas? thanks a lot !
(also , as a debug probe, i use a multilink universal which is correctly detected and used by the flasher)
Adrien