I have a dll compiled with fasm and a c++ console program. When I load the function from the dll file I receive the error 127(0x7F) The specified procedure could not be found.
Dll code: 
    
     ; DLL creation example
format PE GUI 4.0 DLL
entry DllEntryPoint
include 'win32a.inc'
section '.code' code readable executable
proc DllEntryPoint hinstDLL,fdwReason,lpvReserved
        mov     eax,123456
        ret
endp
proc Hello
       mov     eax,12345
       ret
endp
; VOID ShowErrorMessage(HWND hWnd,DWORD dwError);
proc ShowErrorMessage hWnd,dwError
  local lpBuffer:DWORD
        lea     eax,[lpBuffer]
        invoke  FormatMessage,FORMAT_MESSAGE_ALLOCATE_BUFFER+FORMAT_MESSAGE_FROM_SYSTEM,0,[dwError],LANG_NEUTRAL,eax,0,0
        invoke  MessageBox,[hWnd],[lpBuffer],NULL,MB_ICONERROR+MB_OK
        invoke  LocalFree,[lpBuffer]
        ret
endp
; VOID ShowLastError(HWND hWnd);
proc ShowLastError hWnd
        invoke  GetLastError
        stdcall ShowErrorMessage,[hWnd],eax
        ret
endp
section '.idata' import data readable writeable
  library kernel,'KERNEL32.DLL',\
          user,'USER32.DLL'
  import kernel,\
         GetLastError,'GetLastError',\
         SetLastError,'SetLastError',\
         FormatMessage,'FormatMessageA',\
         LocalFree,'LocalFree'
  import user,\
         MessageBox,'MessageBoxA'
section '.edata' export data readable
  export 'ERRORMSG.DLL',\
         ShowErrorMessage,'ShowErrorMessage',\
         ShowLastError,'ShowLastError'
section '.reloc' fixups data discardable
    
 
C++ code:
    
#include <windows.h>
#include <iostream>
using namespace std;
typedef int (__stdcall *f_funci)();
int main()
{
 HINSTANCE hGetProcIDDLL = LoadLibrary("dll.dll");
  if (!hGetProcIDDLL) {
    cout << "could not load the dynamic library" << endl;
    return EXIT_FAILURE;
  }
  // resolve function address here
  f_funci funci = (f_funci)GetProcAddress(hGetProcIDDLL, "Hello");
  if (!funci) {
    cout << "could not locate the function " << funci << GetLastError()<< endl;
    return EXIT_FAILURE;
  }
  cout << "funci() returned " << funci() << endl;
    return 0;
}