Error trying to extract data via HFM objects

Question

I've written a program to extract selected data from HFM (version 11.1.1.3.500) using the API objects. The program (shown at the bottom of this post) is failing on the 2nd of the following 2 lines:
oOption = oOptions.Item(HSV_DATAEXTRACT_OPT_SCENARIO_SUBSET)
oOption.CurrentValue = lBudgetScenario
where oOption is a data load/extract object previously initialized and lBudgetScenario is the long internal ID for our budget scenario.
The error is usually "COM Exception was unhandled" with a result code of "0x800456c7", but, mysteriously, even with no code changes, it sometimes throws the error "FileNotFoundException was not handled", where it says that it could not load "interop.HSXServerlib or one of its dependencies". The second error occurs even though HSXServer was previously initialized in the program and used in conjunction with the login.
I've carefully traced through the VB.NET 2010 code and find that all relevant objects are instantiated and variables correctly assigned. It also occurred to me that the data load DLLs might have been updated when the 11.1.1.3.50 and 500 patches were applied. For that reason, I removed the references to those DLLs, deleted the interop files in the debug and release folders and copied the server versions of those DLLs to my PC. I then restored the DLL references in Visual Studio which recreated the interops. However, the error still occurs.
The ID I'm using (changed to generic names in the code below) has appropriate security and, for example, can be used to manually extract data for the same POV via the HFM client.
I've removed irrelevant lines from the code and substituted a phony ID, password, server name and application name. The line with the error is preceded by the comment "THE LINE BELOW IS THE ONE THAT FAILS".
Imports HSVCDATALOADLib.HSV_DATAEXTRACT_OPTION
Module Module1
Public lActualScenario, lBudgetScenario As Long
Public oClient As HSXCLIENTLib.HsxClient
Public oDataLoad As HSVCDATALOADLib.HsvcDataLoad
Public oOptions As HSVCDATALOADLib.IHsvLoadExtractOptions
Public oOption As HSVCDATALOADLib.IHsvLoadExtractOption
Public oSession As HSVSESSIONLib.HsvSession
Public oServer As HSXSERVERLib.HsxServer
Sub Main()
'Create a client object instance, giving access to
'the methods to logon and create an HFM session
oClient = New HSXCLIENTLib.HsxClient
'Create a server object instance, giving access to
'all server-based methods and properties
oServer = oClient.GetServerOnCluster("SERVERNAME")
'Establish login credentials
oClient.SetLogonInfoSSO("", "MYID", "", "MYPASSWORD")
'Open the application, which will initialize the server
'and session instances as well.
oClient.OpenApplication("SERVERNAME", "Financial Management", "APPLICATION", oServer, oSession)
'Instantiate a data load object instance, which will be used to extract data from
'FRS.
oDataLoad = New HSVCDATALOADLib.HsvcDataLoad
oDataLoad.SetSession(oSession)
'Initialize the data load options interface.
oOptions = oDataLoad.ExtractOptions
'Find the internal ID numbers for various scenarios and years.
'These are required for HFM API function calls.
lActualScenario = GetMemberID(DIMENSIONSCENARIO, "Actual")
lBudgetScenario = GetMemberID(DIMENSIONSCENARIO, "Budget")
'Construct file names for open data.
strFileName = "c:\Temp\FEWND_BudgetData.dat"
strLogFileName = "c:\Temp\FEWND_BudgetData.log"
'Extract data for the current open cycle.
ExtractData("Budget", BudgetYear, "Dec", strFileName, strLogFileName)
End Sub
Sub ExtractData(ByVal strScenario As String, ByVal strYear As String, ByVal strPeriod As String, _
ByVal strFileName As String, ByVal strLogFileName As String)
'Populate the Scenario element.
oOption = oOptions.Item(HSV_DATAEXTRACT_OPT_SCENARIO_SUBSET)
If strScenario = "Actual" Then
oOption.CurrentValue = lActualScenario
Else
'THE LINE BELOW IS THE ONE THAT FAILS
oOption.CurrentValue = lBudgetScenario
End If
End Sub
Function GetMemberID(ByVal lDimID As Long, ByVal strMemLabel As String) As Long
Dim oMetaData As HSVMETADATALib.HsvMetadata
oMetaData = oSession.Metadata
oEntityTreeInfo = oMetaData.Dimension(lDimID)
GetMemberID = oEntityTreeInfo.GetItemID(strMemLabel)
End Function
End Module

Answer 1

I stumbled upon the solution to my problem. The documentation for extracting data via objects defines member ID variables as Longs. In fact, I've always defined such variables as longs in previous object programs and had no problems. It appears that the datal load/extract "option" property of "Currentvalue" is defined as integer. When I changed all of my member ID items (such as the "lBudgetScenario" variable that was the right-side of the failing assignment statement) to be integers, the program worked.