Why simpel MX project will not compile: arm_math.h is missing

[tinu]

Using MX 5.0.1 and create a new project "PrjA" for STboard STNM32F401 Nucleo. No changes or configs. Then generate code and open in TrueStudio. Compilation fails because of:

..\Drivers\CMSIS\DSP_Lib\Source\FilteringFunctions\arm_fir_decimate_init_q15.c:41:22: fatal error: arm_math.h: No such file or directory

But the arm_math.h is existing in the folder C:\STM32\PrjA\Drivers\CMSIS\Include.

Is that normal that I have to add a library path to a MX generated project to compile without error?

Then I try to add this path to the project / properties / Includes or Library Paths and get even worse compilation error missing include files.

[tinu]

Up's choosing the correct Toolchain/IDE "TrueSTUDIO" help's a lot. Compilation is now OK.