The solution file has two projects named "CMSApp".

I am currently upgrading our Kentico 10 solution to Kentico 11. However, When I am running the Kentico Upgrade Utility, it ends up with error:

Exception has been thrown by the target of an invocation.Message: Exception has been thrown by the target of an invocation.
Stack Trace: 
   at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor)
   at System.Reflection.RuntimeMethodInfo.UnsafeInvokeInternal(Object obj, Object[] parameters, Object[] arguments)
   at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   at InstallationHelper.SlnManager.<GetProjects>d__41.MoveNext()
   at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
   at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
   at InstallationHelper.SlnManager.get_Projects()
   at InstallationHelper.SlnManager.CreateSolutionFolder(String folderPath)
   at InstallationHelper.SlnManager.UpdateSolutionFolder(String folderName)
   at Hotfix.Installer.HotfixInstaller.ApplyUpgrade(HotFixItemsEnum items, BackgroundWorker worker, DoWorkEventArgs e)
   at Hotfix.StepLog.BackgroundWorker_DoWork(Object sender, DoWorkEventArgs e)
   at System.ComponentModel.BackgroundWorker.OnDoWork(DoWorkEventArgs e)
   at System.ComponentModel.BackgroundWorker.WorkerThreadStart(Object argument)
The solution file has two projects named "CMSApp".
   at Microsoft.Build.Shared.ProjectFileErrorUtilities.VerifyThrowInvalidProjectFile(Boolean condition, String errorSubCategoryResourceName, BuildEventFileInfo projectFile, Exception innerException, String resourceName, Object[] args)
   at Microsoft.Build.Construction.SolutionParser.ParseSolution()

Please see this link to more details.

It seems, the Kentico Upgrade Utility try to add a new CMSApp project to the solution and then error happens, because there is an existing CMSApp project in the solution.

Not sure what's happening, I suspect some customization on the project are causing this error. But, the error details in log are not informative for me.

Any assistance will be appreciated.

Thank you in advance.