Migrating Defense Solutions objects from ArcGIS 9.3.1 to 10.0 gives Unable to cast COM object error?

Question

I've got an ArcGIS Engine application that uses the IMADtedLayer interface to access VPF DTED catalog layers and adds them to a map. The code ran fine under v9.3.1. I just updated to v10, and now I get:

Unable to cast COM object of type 'ESRI.ArcGIS.DefenseSolutions.MADtedLayerClass' to interface type 'ESRI.ArcGIS.DefenseSolutions.IMADtedLayer'. ... No such interface supported

Here's the relevant C# code:

// geodbFWS is the IFeatureWorkspace object that contains the catalog
// sCatName is the catalog name (string)
ITable catTable = geodbFWS.OpenTable(sCatName);

if (catTable != null)
{
    IMADtedLayer aMADted = new MADtedLayerClass();
    bool bSetup = aMADted.Setup(catTable);
}

The error occurs on the "bool bsetup" line.

I've tried substituting new MADtedLayer(); for new MADtedLayerClass(); - with the same result. I've also uninstalled all ArcGIS components, cleaned out the registry and re-installed. I get the same error.

I'm using MSVisualStudio 2010, and the intellisense recognizes the IMADtedLayer interface, the MADtedLayerClass, and the .Setup method - as well as the fact that it should return a boolean.

I'm running the Windows 7 Professional Operating System. Has anyone else encountered this problem? Any insights will be greatly appreciated!

Answer 1

I've usually encountered problems like this when either the Military Analyst extension installation is corrupted. When you uninstalled ArcGIS, did you uninstall MA before uninstalling ArcGIS? Also, did you get the latest version from http://www.esri.com/software/arcgis/defense-solutions/download-ma.html?

Answer 2

I found a workaround for this problem, but I'm not sure we've fully identified the cause.

We were running this code in a unit test following the upgrade from ArcGIS 9.3 to 10.0. It worked prior to the upgrade, but not after. That's how the problem was initially identified.

Eventually, I ran this code outside of the unit test, and it worked. Further investigation indicated that it only fails when run inside an nUnit unit test. It works fine using Microsoft's unit test framework. So we will run this test without nUnit.

It's idle speculation on my part, but I'm wondering if there is something either related to one of ... threading, licensing, underlying COM objects, or 64-bit operating system.