Visual basic with external .ocx control => access violation - vb.net

Question

I'm new to this site and I'm going to start immediately with a question.
Currently I'm working on a thesis but I'm a stuck at this moment. I've been asked to control an IP-camera via Beckhoff Twincat3. As this is based on visual studio, I thought it might be a good idea to start in visual basic to test and debug everything I code. Everything I do results in AccessViolation.
System.AccessViolationException was unhandled
HResult=-2147467261
Message=Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
Source=mscorlib
StackTrace:
at System.RuntimeType.ForwardCallToInvokeMember(String memberName, BindingFlags flags, Object target, Int32[] aWrapperTypes, MessageData& msgData)
at RASplus_WatSearLib._DRASplus_WatSear.setCameraMap(Int16 nCamNum, Int16 postKey, String szSiteName, String szAddr, Int16 nHostCam, String szUser, String szPasswd, Int16 port, Boolean mode, Boolean bUseModem, Boolean useDvrns, String szDvrnsAddr, Int16 dvrnsPort, Int16 audioPort)
at AxRASplus_WatSearLib.AxRASplus_WatSear.setCameraMap(Int16 nCamNum, Int16 postKey, String szSiteName, String szAddr, Int16 nHostCam, String szUser, String szPasswd, Int16 port, Boolean mode, Boolean bUseModem, Boolean useDvrns, String szDvrnsAddr, Int16 dvrnsPort, Int16 audioPort)
at activex_camera.Form1.Button1_Click(Object sender, EventArgs e) in C:\Users\BECKHOFF stage\documents\visual studio 2010\Projects\activex camera\activex camera\Form1.vb:line 41
at System.Windows.Forms.Control.OnClick(EventArgs e)
at System.Windows.Forms.Button.OnClick(EventArgs e)
at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
at System.Windows.Forms.Control.WndProc(Message& m)
at System.Windows.Forms.ButtonBase.WndProc(Message& m)
at System.Windows.Forms.Button.WndProc(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData)
at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
at System.Windows.Forms.Application.Run(ApplicationContext context)
at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.OnRun()
at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.DoApplicationModel()
at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.Run(String[] commandLine)
at activex_camera.My.MyApplication.Main(String[] Args) in 17d14f5c-a337-4978-8281-53493378c1071.vb:line 81
at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.ThreadHelper.ThreadStart()
InnerException:
I'm currently trying to connect with the camera and it results each time in a AccessViolation.
myCam.setCameraMap(i, CShort(0), "10.199.217.144", "10.199.217.144", i, "admin", "", CShort(8016), False, False, False, "dvrnames.net", 10088, 8116)
I hope someone can get me back on track. If .ocx or other files needed, please do not hesitate to contact me.

Answer 1

I asked my teacher if he knew what was wrong and he came up with this :
In the program, I was working with an 'instance' of the activex-control. This resulted in a accessviolation. He fixed it by using the direct control.
After all it made sense. ;)
Sincerely
GiovanniVanAssche