jN forced in submake: disabling jobserver mode

When building a NET+OS Project i receive this warning…
make[1]: warning: -jN forced in submake: disabling jobserver mode.

What version of Netos?
Make sure your paths are correct, do you have other versions of Netos running on this machine.
Please note that Netos 7.5 is supported on a 32 bit windows 7 not a 64 bit.

Netos 7.5 and windows 7 not a 64 bit that’s could explain why compiling and debugging even the simplest demo application seems to give bad results like no serial output… thanks