Procedure works in one workbook but not another

[AlexanderBB]

On the same Excel/computer I have 2 .xlsm files with this procedure

'This code was originally written by Dev Ashish.
'It is not to be altered or distributed,
'except as part of an application.
'You are free to use it in any application,
'provided the copyright notice is left unchanged.
'
'Code Courtesy of
'Dev Ashish

Private Declare Function apiShellExecute Lib "shell32.dll" _
    Alias "ShellExecuteA" _
    (ByVal hWnd As Long, _
    ByVal lpOperation As String, _
    ByVal lpFile As String, _
    ByVal lpParameters As String, _
    ByVal lpDirectory As String, _
    ByVal nShowCmd As Long) _
    As Long

'***App Window Constants***
Public Const WIN_NORMAL = 1         'Open Normal
Public Const WIN_MAX = 2            'Open Maximized
Public Const WIN_MIN = 3            'Open Minimized

'***Error Codes***
Private Const ERROR_SUCCESS = 32&
Private Const ERROR_NO_ASSOC = 31&
Private Const ERROR_OUT_OF_MEM = 0&
Private Const ERROR_FILE_NOT_FOUND = 2&
Private Const ERROR_PATH_NOT_FOUND = 3&
Private Const ERROR_BAD_FORMAT = 11&

'***************Usage Examples***********************
'Open a folder:     ?fHandleFile("C:\TEMP\",WIN_NORMAL)
'Call Email app:    ?fHandleFile("mailto:dash10@hotmail.com",WIN_NORMAL)
'Open URL:          ?fHandleFile("http://home.att.net/~dashish",WIN_NORMAL)
'Handle Unknown extensions (call Open With Dialog):
'                   ?fHandleFile("C:\TEMP\TestThis",Win_Normal)
'Start Access instance:
'                   ?fHandleFile("I:\mdbs\CodeNStuff.mdb", Win_NORMAL)
'****************************************************

Function fHandleFile(stFile As String, lShowHow As Long)
Dim lRet As Long, varTaskID As Variant
Dim stRet As String
    'First try ShellExecute
    lRet = apiShellExecute(hWndAccessApp, vbNullString, _
            stFile, vbNullString, vbNullString, lShowHow)
            
    If lRet > ERROR_SUCCESS Then
        stRet = vbNullString
        lRet = -1
    Else
        Select Case lRet
            Case ERROR_NO_ASSOC:
                'Try the OpenWith dialog
                varTaskID = Shell("rundll32.exe shell32.dll,OpenAs_RunDLL " _
                        & stFile, WIN_NORMAL)
                lRet = (varTaskID <> 0)
            Case ERROR_OUT_OF_MEM:
                stRet = "Error: Out of Memory/Resources. Couldn't Execute! """
            Case ERROR_FILE_NOT_FOUND:
                stRet = "Error: File not found.  Couldn't Execute!"
            Case ERROR_PATH_NOT_FOUND:
                stRet = "Error: Path not found. Couldn't Execute!"
            Case ERROR_BAD_FORMAT:
                stRet = "Error:  Bad File Format. Couldn't Execute!"
            Case Else:
        End Select
    End If
    fHandleFile = lRet & IIf(stRet = "", vbNullString, ", " & stRet)
End Function

It normally works fine but in one file it goes to error variable not defined and highlights hWndAccessApp.
I have the exact same references in both workbooks.
r-clicking hWndAccessApp. and Definitions tells me identifier under cursor is not recognized.
But it does this in both the working non-working code.
One difference was the file was originally .xlxs with no code, but I saved as .xlsm, enabled macros and pasted the same code in.
I didn't think that would be a problem.
I don't quite understand the api statement, can anyone tell me why it's variable not found. Many thanks.

 

[AlexanderBB]

ah, sorry must be going blind.
i missed the MiscrosofrAccess12 Object Library reference. Now OK.

 

[Alex Blakenburg]

Since you can't open the reference dialogue box from 2 workbooks at once. I find it can be helpful to take a snip Win+Shift+S of one of them so that you can position it side by side with the other one when you open it.

 

[AlexanderBB]

Crikey, never knew that! Great tip. I'd print screen and pasted into PSP and cropped. That's redundant now