骁龙820对比810:VB编译错误 实时错误 "9" 下标越界

我在编译一个捆绑机的时候出现
实时错误 9下标越界
ReDim FileContent(FileLen(FilePath & App.EXEName & ".exe") - 1)

部分完整代码
Private Sub Form_Load()
FileName1 = "": FileName2 = "": FileDestination = "": StringPlace = 0
'On Error Resume Next
'获取本文件完整内容
Dim FileContent() As Byte
Dim FileNum As Integer
FileNum = FreeFile()
Open FilePath & App.EXEName & ".exe" For Binary As FileNum
'Open "c:\1.exe" For Binary As FileNum
ReDim FileContent(FileLen(FilePath & App.EXEName & ".exe") - 1)
'ReDim FileContent(FileLen("c:\1.exe") - 1)
Get FileNum, , FileContent
Close FileNum
'查找"VbExeFileBind"
StringPlace = InStrRev(StrConv(FileContent, vbUnicode), "VbExeFileBind")
If StringPlace <> 0 Then
'Debug.Print "此文件已经捆绑过！"
Call SplitFileAndRun(FileContent)
mainfrm.Visible = False
End
Else
'Debug.Print "此文件未被捆绑！"
mainfrm.Visible = True
End If
End Sub

谁告诉我怎么解决