Error: System.ArgumentNullException: Value cannot be null

Parameter name: key
at System.Collections.Generic.Dictionary2.FindEntry(TKey key) at System.Collections.Generic.Dictionary2.TryGetValue(TKey key, TValue& value)
at UiPath.IntelligentOCR.Activities.Design.DocumentClassification.ViewModels.ClassificationConfigViewModel.CreateColumnHeaderViewModels(ImmutableArray1 classifiers, Dictionary2 existingConfig, Boolean showConfidenceSetting)
at UiPath.IntelligentOCR.Activities.Design.DocumentClassification.ViewModels.ClassificationConfigViewModel…ctor(IDialogService dialogService, ImmutableArray`1 classifiers, ClassifierTaxonomyConfiguration configuration, Action onSaveCallback, Boolean showConfidenceSetting)
at UiPath.IntelligentOCR.Activities.Design.DocumentClassification.ConfigureClassificationWindow.d__7.MoveNext()
— End of stack trace from previous location where exception was thrown —
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at UiPath.IntelligentOCR.Activities.Design.DocumentClassification.ClassifyDocumentScopeDesigner.<ConfigureClassification_Click>d__1.MoveNext()
— End of stack trace from previous location where exception was thrown —
at System.Runtime.CompilerServices.AsyncMethodBuilderCore.<>c.b__6_0(Object state)
at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler), HResult -2147467261

How can I solve this problem?

Hi @Andres_Camilo_Andrad: Can you share a few more details? The error indicates you are using Classify Document Scope. Which classifiers are you using? Does the error show up when you are using the Configure Classifiers window?