Hey Julen,
Small note: The latest (at least my sources) of MQX4 is version 4.2.0.2 (4.2, patch 2).
Version 4.2 is also referred on that Toradex page you mentioned, MQX™ on the Cortex-M4 of a Colibri VF61 .
I have ran that hello world example on Toradex's Colibri while back, following their howto, and it worked fine.
One thing I want to note: make sure you reset your SoC properly before any code example change / re-upload. In my experience, it is not possible for MQX to initialize properly unless from a complete clean system out of reset. That's my observation and current state of my code, and I have asked multiple times about it various places, but never got to understand why.
(Besides that you cannot re-set/restart M4 on Vybrid of course.)
If you resolved your issue, please share what helped you. I'm also working on the Toradex VF61x module.
(Note: I'm not from NXP, so I guess take everything I say as suspicious :smileyhappy: )