title: vb.net (4.0 framework) form not loading
body: <p>hoping someone might be able to shine some light on this issue.</p>
  
  <p>I have a form in vb.net (using VS2010, .net 4.0 framework) that will not load, but instead errors out in the variable declarations. I have the following two lines in my declarations</p>
  
  <pre><code>    Dim rpRBuilders As New rpRBuilder_2010.rp_RBuilder
      Public CR As New ReportDocument
  </code></pre>
  
  <p>Now, when I place my breakpoints on each line, it breaks at the first line, but errors out upon processing "Public CR As New ReportDocument" and receive a generic error screen: </p>
  
  <p><img src="https://i.stack.imgur.com/RcsPJ.png" alt="Error Screen"></p>
  
  <p>I have downloaded and imported all crystal report libraries for VS2010, and am using versions 13.0.2000.0 in my project.</p>
  
  <p>The exception detail provided isn't especially helpful to me, but one of you may be able to understand it better than I:</p>
  
  <pre><code>    System.InvalidOperationException was unhandled
      Message=An error occurred creating the form. See Exception.InnerException for
      details. The error is: Invalid ServicedComponent-derived classes were found in the
      assembly.
      (Classes must be public, concrete, have a public default constructor, and meet all 
      other ComVisibility requirements)
      Source=ReportBuilder2010
      StackTrace:
      at ReportBuilder2010.My.MyProject.MyForms.Create__Instance__[T](T Instance) in 
      17d14f5c-a337-4978-8281-53493378c1071.vb:line 190
      at ReportBuilder2010.My.MyProject.MyForms.get_frmReports()
      at ReportBuilder2010.frmReports.Main() in C:\To Back Up\Repository\Report Builder  
      2010\ReportBuilder2010\ReportBuilder2010\frmReports.Designer.vb:line 0
      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.Run(ExecutionContext executionContext, 
      ContextCallback callback, Object state, Boolean ignoreSyncCtx)
      at System.Threading.ExecutionContext.Run(ExecutionContext executionContext,  
      ContextCallback callback, Object state)
      at System.Threading.ThreadHelper.ThreadStart()
      InnerException: System.EnterpriseServices.RegistrationException
      Message=Invalid ServicedComponent-derived classes were found in the assembly.
      (Classes must be public, concrete, have a public default constructor, and meet all 
      other ComVisibility requirements)
      Source=System.EnterpriseServices
      StackTrace:
          at System.EnterpriseServices.RegistrationThreadWrapper.PropInstallResult()
          at        
      System.EnterpriseServices.RegistrationHelper.InstallAssemblyFromConfig
      (RegistrationConfig&amp; regConfig)
          at System.EnterpriseServices.RegistrationHelper.InstallAssembly(String 
      assembly, String&amp; application, String partition, String&amp; tlb, InstallationFlags 
      installFlags)
          at    System.EnterpriseServices.RegistrationHelper.System.EnterpriseServices.
  
      Thunk.IThunkInstallation.DefaultInstall(String asm)
          at System.EnterpriseServices.Thunk.Proxy.RegisterAssembly(Assembly assembly)
          at System.EnterpriseServices.Thunk.Proxy.LazyRegister(Guid id, Type 
      serverType, Boolean checkCache)
          at System.EnterpriseServices.Thunk.Proxy.CoCreateObject(Type serverType, 
      Boolean bQuerySCInfo, Boolean&amp; bIsAnotherProcess, String&amp; uri)
          at System.EnterpriseServices.ServicedComponentProxyAttribute.
      CreateInstance(Type serverType)
          at System.Runtime.Remoting.Activation.ActivationServices.IsCurrentContextOK
      (RuntimeType serverType, Object[] props, Boolean bNewObj)
          at ReportBuilder2010.frmReports..ctor() in C:\To Back Up\Repository\Report 
      Builder 2010\ReportBuilder2010\ReportBuilder2010\frmReports.vb:line 27
  </code></pre>
  
  <p>Thank you all in advance for your help, I can provide more details if needed.    </p>