4399 in ComSave.

Code:
    Procedure ComSave String llfilename
        Handle hDispatchDriver
        Get phDispatchDriver to hDispatchDriver
        Send PrepareParams to hDispatchDriver 1
        Send DefineParam to hDispatchDriver OLE_VT_BSTR llfilename
        Send InvokeComMethod to hDispatchDriver 1 OLE_VT_VOID  <<<<<
    End_Procedure
This has been working for months!
The xlsx being updated is not RO. It has processed and written to 348 lines of excel. This is literally the last line before destroyallobjects. What am I missing. 19.1 and 20/32.