Q: Unable to add ProgressBar or Panel to Form I'm working on something in Visual Studio 2012, but for some reason cannot add progress bars or panels to the form from the toolbox. Progress bars weren't working the other day but panels have only just stopped working today, and nothing I can think of has changed between now and then. I've had a look at some other controls (textbox, button, label) and they still work fine at the moment. I've tried creating a panel programatically and that didn't work either. Something to do with references maybe?
This is the error I get:
Failed to create component 'ProgressBar'. The error message follows:

'System.Runtime.InteropServices.COMException (0x80004005): Error
  HRESULT E_FAIL has been returned from a call to a COM component.  at
  VSLangProj.References.Add(String bstrPath)    at 
  Microsoft.VisualStudio.Design.VSTypeResolutionService.System.ComponentModel.Design.ITypeResolutionService.ReferenceAssembly(AssemblyName
  name)     at
  Microsoft.VisualStudio.Design.Serialization.CodeDom.AggregateTypeResolutionService.ReferenceAssembly(AssemblyName
  name)     at System.Drawing.Design.ToolboxItem.GetType(IDesignerHost
  host, AssemblyName assemblyName, String typeName, Boolean reference)
    at
  System.Drawing.Design.ToolboxItem.CreateComponentsCore(IDesignerHost
  host)     at
  System.Drawing.Design.ToolboxItem.CreateComponentsCore(IDesignerHost
  host, IDictionary defaultValues)  at
  System.Drawing.Design.ToolboxItem.CreateComponents(IDesignerHost host,
  IDictionary defaultValues)    at System.Windows.Form.Des...'

Anyone got any suggestions? Thanks.

A: Have you tried:


*

*Cleaning the solution & rebuilding?

*Closing VS and re-opening?

*Opening a 2nd instance of Visual Studio, Choosing Debug -> Attach to Process and selecting the 1st instance of VS? 


About that last one. VS is running code inside the IDE even when your application code is not running. It uses Reflection to examine the properties of a control for example. Sometimes using VS to debug VS (as odd as it sounds) will yield some good results. 
