Within the Shell Function, the following lines exist. So this gets tripped up on 64 bit systems if LongPtr is used (best guess). If I comment out Option Explicit, then everything runs OK with LongPtr as part of the code. So maybe I should just remove the Option Explicit and leave the code with the LongPtr?

Dim lResult As Long
Dim lTaskID As Long
Dim lProcess As Long
Dim lExitCode As Long