c++ - Visual Studio 2017 errors on standard headers

Question

I just upgraded to Visual Studio 2017 Community Edition and I have trouble loading standard header files. I get 507 errors from various header files. Here are some snippets:

Some of the errors:

Severity    Code    Description Project File    Line    Suppression State
Error (active)  E1696   cannot open source file "errno.h"   RPGWorld    c:Program Files (x86)Microsoft Visual Studio2017CommunityVCToolsMSVC14.10.25017includecerrno  7   
Error (active)  E1696   cannot open source file "float.h"   RPGWorld    c:Program Files (x86)Microsoft Visual Studio2017CommunityVCToolsMSVC14.10.25017includecfloat  7   
Error (active)  E0282   the global scope has no "acosf" RPGWorld    c:Program Files (x86)Microsoft Visual Studio2017CommunityVCToolsMSVC14.10.25017includecmath   629 
Error (active)  E0282   the global scope has no "asinf" RPGWorld    c:Program Files (x86)Microsoft Visual Studio2017CommunityVCToolsMSVC14.10.25017includecmath   629 
Error (active)  E0282   the global scope has no "atanf" RPGWorld    c:Program Files (x86)Microsoft Visual Studio2017CommunityVCToolsMSVC14.10.25017includecmath   630 
Error (active)  E0282   the global scope has no "atan2f"    RPGWorld    c:Program Files (x86)Microsoft Visual Studio2017CommunityVCToolsMSVC14.10.25017includecmath   630 
Error (active)  E0282   the global scope has no "ceilf" RPGWorld    c:Program Files (x86)Microsoft Visual Studio2017CommunityVCToolsMSVC14.10.25017includecmath   630 
Error (active)  E0282   the global scope has no "cosf"  RPGWorld    c:Program Files (x86)Microsoft Visual Studio2017CommunityVCToolsMSVC14.10.25017includecmath   631 
Error (active)  E0282   the global scope has no "coshf" RPGWorld    c:Program Files (x86)Microsoft Visual Studio2017CommunityVCToolsMSVC14.10.25017includecmath   631 
Error (active)  E0282   the global scope has no "swprintf"  RPGWorld    c:Program Files (x86)Microsoft Visual Studio2017CommunityVCToolsMSVC14.10.25017includecwchar  21  
Error (active)  E0282   the global scope has no "swscanf"   RPGWorld    c:Program Files (x86)Microsoft Visual Studio2017CommunityVCToolsMSVC14.10.25017includecwchar  21  
Error (active)  E0282   the global scope has no "ungetwc"   RPGWorld    c:Program Files (x86)Microsoft Visual Studio2017CommunityVCToolsMSVC14.10.25017includecwchar  21  
Error (active)  E0282   the global scope has no "vfwprintf" RPGWorld    c:Program Files (x86)Microsoft Visual Studio2017CommunityVCToolsMSVC14.10.25017includecwchar  22  
Error (active)  E0282   the global scope has no "vswprintf" RPGWorld    c:Program Files (x86)Microsoft Visual Studio2017CommunityVCToolsMSVC14.10.25017includecwchar  22  
Error (active)  E0282   the global scope has no "vwprintf"  RPGWorld    c:Program Files (x86)Microsoft Visual Studio2017CommunityVCToolsMSVC14.10.25017includecwchar  22  
Error (active)  E0282   the global scope has no "wcrtomb"   RPGWorld    c:Program Files (x86)Microsoft Visual Studio2017CommunityVCToolsMSVC14.10.25017includecwchar  23  
Error (active)  E0282   the global scope has no "wprintf"   RPGWorld    c:Program Files (x86)Microsoft Visual Studio2017CommunityVCToolsMSVC14.10.25017includecwchar  23  
Error (active)  E0282   the global scope has no "wscanf"    RPGWorld    c:Program Files (x86)Microsoft Visual Studio2017CommunityVCToolsMSVC14.10.25017includecwchar  23  
Error (active)  E0282   the global scope has no "wcsrtombs" RPGWorld    c:Program Files (x86)Microsoft Visual Studio2017CommunityVCToolsMSVC14.10.25017includecwchar  24  
Error (active)  E0282   the global scope has no "wcstol"    RPGWorld    c:Program Files (x86)Microsoft Visual Studio2017CommunityVCToolsMSVC14.10.25017includecwchar  24  
Error (active)  E0282   the global scope has no "wcscat"    RPGWorld    c:Program Files (x86)Microsoft Visual Studio2017CommunityVCToolsMSVC14.10.25017includecwchar  24  
Error (active)  E0282   the global scope has no "wcschr"    RPGWorld    c:Program Files (x86)Microsoft Visual Studio2017CommunityVCToolsMSVC14.10.25017includecwchar  25  
Error (active)  E0282   the global scope has no "wcscmp"    RPGWorld    c:Program Files (x86)Microsoft Visual Studio2017CommunityVCToolsMSVC14.10.25017includecwchar  25  
Error (active)  E0282   the global scope has no "wcscoll"   RPGWorld    c:Program Files (x86)Microsoft Visual Studio2017CommunityVCToolsMSVC14.10.25017includecwchar  25  
Error (active)  E0282   the global scope has no "wcscpy"    RPGWorld    c:Program Files (x86)Microsoft Visual Studio2017CommunityVCToolsMSVC14.10.25017includecwchar  26  
Error (active)  E0282   the global scope has no "wcscspn"   RPGWorld    c:Program Files (x86)Microsoft Visual Studio2017CommunityVCToolsMSVC14.10.25017includecwchar  26  
Error (active)  E0282   the global scope has no "wcslen"    RPGWorld    c:Program Files (x86)Microsoft Visual Studio2017CommunityVCToolsMSVC14.10.25017includecwchar  26  
Error (active)  E0282   the global scope has no "wcsncat"   RPGWorld    c:Program Files (x86)Microsoft Visual Studio2017CommunityVCToolsMSVC14.10.25017includecwchar  27  
Error (active)  E0282   the global scope has no "wcsncmp"   RPGWorld    c:Program Files (x86)Microsoft Visual Studio2017CommunityVCToolsMSVC14.10.25017includecwchar  27  
Error (active)  E0282   the global scope has no "wcsncpy"   RPGWorld    c:Program Files (x86)Microsoft Visual Studio2017CommunityVCToolsMSVC14.10.25017includecwchar  27  
Error (active)  E0282   the global scope has no "wcspbrk"   RPGWorld    c:Program Files (x86)Microsoft Visual Studio2017CommunityVCToolsMSVC14.10.25017includecwchar  28  
Error (active)  E0282   the global scope has no "wcsrchr"   RPGWorld    c:Program Files (x86)Microsoft Visual Studio2017CommunityVCTools
Error (active)  E0260   explicit type is missing ('int' assumed)    RPGWorld    c:Program Files (x86)Microsoft Visual Studio2017CommunityVCToolsMSVC14.10.25017includextgmath.h   212 
Error (active)  E0757   variable "size_t" is not a type name    RPGWorld    c:UsersFazilDocumentsVisual Studio 2017ProjectsLocalRPGWorldpackagessfml-system.2.4.0.0uild
ativeincludeSFMLGraphicsGlsl.inl    40  
Error (active)  E0757   variable "size_t" is not a type name    RPGWorld    c:UsersFazilDocumentsVisual Studio 2017ProjectsLocalRPGWorldpackagessfml-system.2.4.0.0uild
ativeincludeSFMLGraphicsTexture.hpp 159 
Error (active)  E0757   variable "size_t" is not a type name    RPGWorld    c:UsersFazilDocumentsVisual Studio 2017ProjectsLocalRPGWorldpackagessfml-system.2.4.0.0uild
ativeincludeSFMLGraphicsVertexArray.hpp 64  
Error (active)  E0757   variable "size_t" is not a type name    RPGWorld    c:UsersFazilDocumentsVisual Studio 2017ProjectsLocalRPGWorldpackagessfml-system.2.4.0.0uild
ativeincludeSFMLGraphicsVertexArray.hpp 72  
Error (active)  E0757   variable "size_t" is not a type name    RPGWorld    c:UsersFazilDocumentsVisual Studio 2017ProjectsLocalRPGWorldpackagessfml-system.2.4.0.0uild
ativeincludeSFMLGraphicsVertexArray.hpp 88  
Error (active)  E0757   variable "size_t" is not a type name    RPGWorld    c:UsersFazilDocumentsVisual Studio 2017ProjectsLocalRPGWorldpackagessfml-system.2.4.0.0uild
ativeincludeSFMLGraphicsVertexArray.hpp 104 
Error (active)  E0757   variable "size_t" is not a type name    RPGWorld    c:UsersFazilDocumentsVisual Studio 2017ProjectsLocalRPGWorldpackagessfml-system.2.4.0.0uild
ativeincludeSFMLGraphicsVertexArray.hpp 129 
Error (active)  E0757   variable "size_t" is not a type name    RPGWorld    c:UsersFazilDocumentsVisual Studio 2017ProjectsLocalRPGWorldpackagessfml-system.2.4.0.0uild
ativeincludeSFMLSystemString.hpp    58  
Error (active)  E0757   variable "size_t" is not a type name    RPGWorld    c:UsersFazilDocumentsVisual Studio 2017ProjectsLocalRPGWorldpackagessfml-system.2.4.0.0uild
ativeincludeSFMLSystemString.hpp    332 
Error (active)  E0757   variable "size_t" is not a type name    RPGWorld    c:UsersFazilDocumentsVisual Studio 2017ProjectsLocalRPGWorldpackagessfml-system.2.4.0.0uild
ativeincludeSFMLSystemString.hpp    345 
Error (active)  E0757   variable "size_t" is not a type name    RPGWorld    c:UsersFazilDocumentsVisual Studio 2017ProjectsLocalRPGWorldpackagessfml-system.2.4.0.0uild
ativeincludeSFMLSystemString.hpp    365 
Error (active)  E0757   variable "size_t" is not a type name    RPGWorld    c:UsersFazilDocumentsVisual Studio 2017ProjectsLocalRPGWorldpackagessfml-system.2.4.0.0uild
ativeincludeSFMLSystemString.hpp    387 
Error (active)  E0757   variable "size_t" is not a type name    RPGWorld    c:UsersFazilDocumentsVisual Studio 2017ProjectsLocalRPGWorldpackagessfml-system.2.4.0.0uild
ativeincludeSFMLSystemString.hpp    387 
Error (active)  E0757   variable "size_t" is not a type name    RPGWorld    c:UsersFazilDocumentsVisual Studio 2017ProjectsLocalRPGWorldpackagessfml-system.2.4.0.0uild
ativeincludeSFMLSystemString.hpp    399 
Error (active)  E0757   variable "size_t" is not a type name    RPGWorld    c:UsersFazilDocumentsVisual Studio 2017ProjectsLocalRPGWorldpackagessfml-system.2.4.0.0uild
ativeincludeSFMLSystemString.hpp    413 
Error (active)  E0757   variable "size_t" is not a type name    RPGWorld    c:UsersFazilDocumentsVisual Studio 2017ProjectsLocalRPGWorldpackagessfml-system.2.4.0.0uild
ativeincludeSFMLSystemString.hpp    413 
Error (active)  E0757   variable "size_t" is not a type name    RPGWorld    c:UsersFazilDocumentsVisual Studio 2017ProjectsLocalRPGWorldpackagessfml-system.2.4.0.0uild
ativeincludeSFMLSystemString.hpp    427 
Error (active)  E0757   variable "size_t" is not a type name    RPGWorld    c:UsersFazilDocumentsVisual Studio 2017ProjectsLocalRPGWorldpackagessfml-system.2.4.0.0uild
ativeincludeSFMLSystemString.hpp    427 
Error (active)  E0757   variable "size_t" is not a type name    RPGWorld    c:UsersFazilDocumentsVisual Studio 2017ProjectsLocalRPGWorldpackagessfml-system.2.4.0.0uild
ativeincludeSFMLSystemString.hpp    456 
Error (active)  E0757   variable "size_t" is not a type name    RPGWorld    c:UsersFazilDocumentsVisual Studio 2017ProjectsLocalRPGWorldpackagessfml-system.2.4.0.0uild
ativeincludeSFMLSystemString.hpp    456 
Error (active)  E0020   identifier "rand" is undefined  RPGWorld    c:UsersFazilDocumentsVisual Studio 2017ProjectsLocalRPGWorldRPGWorldBlocks.cpp 23  
Error   C1083   Cannot open include file: 'corecrt.h': No such file or directory    RPGWorld    c:program files (x86)microsoft visual studio2017communityvcoolsmsvc14.10.25017includecrtdefs.h   10  
Error   C1083   Cannot open include file: 'corecrt.h': No such file or directory    RPGWorld    c:program files (x86)microsoft visual studio2017communityvcoolsmsvc14.10.25017includecrtdefs.h   10  
Error   C1083   Cannot open include file: 'corecrt.h': No such file or directory    RPGWorld    c:program files (x86)microsoft visual studio2017communityvcoolsmsvc14.10.25017includecrtdefs.h   10  
Error   C1083   Cannot open include file: 'corecrt.h': No such file or directory    RPGWorld    c:program files (x86)microsoft visual studio2017communityvcoolsmsvc14.10.25017includecrtdefs.h   10  
Error   C1083   Cannot open include file: 'corecrt.h': No such file or directory    RPGWorld    c:program files (x86)microsoft visual studio2017communityvcoolsmsvc14.10.25017includecrtdefs.h   10  
Error   C1083   Cannot open include file: 'corecrt.h': No such file or directory    RPGWorld    c:program files (x86)microsoft visual studio2017communityvcoolsmsvc14.10.25017includecrtdefs.h   10  
Error   C1083   Cannot open include file: 'corecrt.h': No such file or directory    RPGWorld    c:program files (x86)microsoft visual studio2017communityvcoolsmsvc14.10.25017includecrtdefs.h   10  
Error   C1083   Cannot open include file: 'corecrt.h': No such file or directory    RPGWorld    c:program files (x86)microsoft visual studio2017communityvcoolsmsvc14.10.25017includecrtdefs.h   10  

I never had this issue with Visual St

Answer 1

I got the errors to go away by installing the Windows Universal CRT SDK component, which adds support for legacy Windows SDKs. You can install this using the Visual Studio Installer:

If the problem still persists, you should change the Target SDK in the Visual Studio Project : check whether the Windows SDK version is 10.0.15063.0.

In : Project -> Properties -> General -> Windows SDK Version -> select 10.0.15063.0.

Then errno.h and other standard files will be found and it will compile.