When i compil my program it show Build target 'NTM8051' compiling UCOS_II.C... assembling ..\out\UCOS_II.src... compiling OS_CPU_C.C... ..\PORT\OS_CPU_C.C(63): error C231: 'OSTaskStkInit': redefinition assembling OS_CPU_A.ASM... compiling mainfile.C... compiling function.C... Target not created i try to compil my example program but it have error C231 . please advice me