When I run Teaport_Wars_2010 there was such

run error:

eapotWars_2010Win32Debug.exe': Loaded 'C:\gamecode4\dev\Source\Lib\Win32Debug\TeapotWars_2010Win32Debug.exe', Symbols loaded.
'TeapotWars_2010Win32Debug.exe': Loaded 'C:\Windows\System32\ntdll.dll', Cannot find or open the PDB file
'TeapotWars_2010Win32Debug.exe': Loaded 'C:\Windows\System32\kernel32.dll', Cannot find or open the PDB file

What does this error means?