@AT - I do not understand how to invoke the document handler when a document is loaded. I have a bare bones add in with XCAD and have the following in my add in OnConnect():

        public override void OnConnect()
        {
            Application.Documents.RegisterHandler();
            CommandManager.AddCommandGroup().CommandClick += DoEFQuery;
            base.OnConnect();
        }

My DocumentHandler class looks like this:

    class DocumentHandler : SwDocumentHandler
    {

        private IXApplication m_App;
        private IXDocument m_Model;

        publicvoid Init(IXApplication app, IXDocument model)
        {
            m_App = app;
            m_Model = model;
            m_Model.StorageReadAvailable += OnStorageReadAvailable;
            m_Model.StorageWriteAvailable += OnStorageWriteAvailable;
        }

        protected override void AttachPartEvents(PartDoc part)
        {

        }

        protected override void DetachAssemblyEvents(AssemblyDoc assm)
        {

        }

        private void HandleStorage(ISwDocument doc)
        {
            doc.StorageReadAvailable += OnStorageReadAvailable;
            doc.StorageWriteAvailable += OnStorageWriteAvailable;
        }

        private void OnStorageWriteAvailable(IXDocument doc)
        {
            MessageBox.Show("Storage write available");
        }

        private void OnStorageReadAvailable(IXDocument doc)
        {
            MessageBox.Show("Storage read available");
        }
    }

When I start debugging Solidworks loads and the addin is registered. When I open a document the document handler does not run. What am I missing?

**EDIT** - Using the debugging capability of XCAD I see the following errors when Solidworks starts up. I have added the exception and the line before the exception:

'SLDWORKS.exe' (CLR v4.0.30319: DefaultDomain): Loaded 'C:\\WINDOWS\\Microsoft.Net\\assembly\\GAC_MSIL\\System.Core\\v4.0_4.0.0.0__b77a5c561934e089\\System.Core.dll'. Symbols loaded.
Exception thrown: 'System.IO.FileNotFoundException' in mscorlib.dll

...

'SLDWORKS.exe' (CLR v4.0.30319: DefaultDomain): Loaded 'C:\\Program Files\\SOLIDWORKS Corp\\SOLIDWORKS\\Xceed.Compression.v5.1.dll'. Module was built without symbols.
Exception thrown: 'System.IO.FileNotFoundException' in mscorlib.dll

...

'SLDWORKS.exe' (CLR v4.0.30319: DefaultDomain): Loaded 'C:\\WINDOWS\\Microsoft.Net\\assembly\\GAC_MSIL\\System.Deployment\\v4.0_4.0.0.0__b03f5f7f11d50a3a\\System.Deployment.dll'. Symbols loaded.
Exception thrown: 'System.Deployment.Application.InvalidDeploymentException' in System.Deployment.dll

...

Then XCAD starts OK:

XCad.AddIn.SharplineAddIn: [Debug]Loading add-in
XCad.AddIn.SharplineAddIn: [Debug]Creating command group: 0
XCad.AddIn.SharplineAddIn: [Debug]Command ids changed: False
XCad.AddIn.SharplineAddIn: [Debug]Created command Output to robot language:0 for 0
XCad.AddIn.SharplineAddIn: [Debug]Command group-0 Id: No Toolbar
XCad.AddIn.SharplineAddIn: [Debug]Command-0 Id: 32761
XCad.AddIn.SharplineAddIn: [Debug]Creating command tab box

Then when I load a partDoc I get:

XCad.AddIn.SharplineAddIn: [Debug]Adding 'Part1.SLDPRT' to the dispatch queue
XCad.AddIn.SharplineAddIn: [Debug]Dispatching all (1) models
XCad.AddIn.SharplineAddIn: [Debug]Dispatched 'Part1.SLDPRT'
XCad.AddIn.SharplineAddIn: [Debug]Cleared models queue