Please check whether the setting for include file's searching path is correct.
For example, if you use kinetis,
1) Put your mouse on the source file folder in Project Panel, then right click mouse to select 'Properties'
2) Go to C/C++ Build-> Settings, under <Tool Settings> tab, go to ARM compiler -> Input, whether the path for the specific file is listed here? If not, please add it.
3) Go to C/C++ General-> Paths and Symbols, under <Includes> tab, go to C source File, whether the path for the specific file is listed here? If not, please add it.
if the problem persists, please upload your project here. we can check.