Declare function no longer works

[msnyder701]

I'm using Excel for Office 365 and up until a couple of weeks ago (or thereabouts) this statement gave no trouble:

Private Declare Function apiShowWindow Lib "user32" Alias "ShowWindow" _
            (ByVal hWnd As Long, ByVal nCmdShow As Long) As Long

Now, trying to save a program with this line in it gives me a sharing violation and an access violation. Can someone please help? Thanks!!