Hi Michiel,
C++ compiler is licensed and it is available in Professional Edition license only.
If you open the license.dat file located in "<CW home directory>\MCU\license.dat" you should see :
INCREMENT ProfessionalEditionMCU metrowks 11.1...
for more details please see the CodeWarrior Quick Reference Guide: https://www.nxp.com/docs/en/fact-sheet/950-00437.pdf
Hope it helps.
Stan