FirebirdSql.Data.FirebirdClient.FbException occurred
  HResult=0x80004005
  Message=Unable to complete network request to host "dbserver".
  Source=<Cannot evaluate the exception source>
  StackTrace:
   at FirebirdSql.Data.FirebirdClient.FbConnectionInternal.Connect()
   at FirebirdSql.Data.FirebirdClient.FbConnectionPoolManager.Pool.CreateNewConnectionIfPossibleImpl(FbConnectionString connectionString)
   at FirebirdSql.Data.FirebirdClient.FbConnectionPoolManager.Pool.GetConnection(FbConnection owner)
   at FirebirdSql.Data.FirebirdClient.FbConnectionPoolManager.Get(FbConnectionString connectionString, FbConnection owner)
   at FirebirdSql.Data.FirebirdClient.FbConnection.Open()
   at PDV_WPF.FDBDataSetTableAdapters.TB_ESTOQUETableAdapter.ChecaPorDescricao(String Param1) in C:\Users\Usuário\Documents\Visual Studio 2017\Projects\PDV\PDV_WPF\FDBDataSet.Designer.cs:line 13704
   at PDV_WPF.Caixa.ACBox_KeyDown(Object sender, KeyEventArgs e) in C:\Users\Usuário\Documents\Visual Studio 2017\Projects\PDV\PDV_WPF\Telas\Caixa.xaml.cs:line 206
   at System.Windows.Input.KeyEventArgs.InvokeEventHandler(Delegate genericHandler, Object genericTarget)
   at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
   at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
   at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
   at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
   at System.Windows.UIElement.RaiseTrustedEvent(RoutedEventArgs args)
   at System.Windows.UIElement.RaiseEvent(RoutedEventArgs args, Boolean trusted)
   at System.Windows.Input.InputManager.ProcessStagingArea()
   at System.Windows.Input.InputManager.ProcessInput(InputEventArgs input)
   at System.Windows.Input.InputProviderSite.ReportInput(InputReport inputReport)
   at System.Windows.Interop.HwndKeyboardInputProvider.ReportInput(IntPtr hwnd, InputMode mode, Int32 timestamp, RawKeyboardActions actions, Int32 scanCode, Boolean isExtendedKey, Boolean isSystemKey, Int32 virtualKey)
   at System.Windows.Interop.HwndKeyboardInputProvider.ProcessKeyAction(MSG& msg, Boolean& handled)
   at System.Windows.Interop.HwndSource.CriticalTranslateAccelerator(MSG& msg, ModifierKeys modifiers)
   at System.Windows.Interop.HwndSource.OnPreprocessMessage(Object param)
   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)
   at System.Windows.Threading.Dispatcher.LegacyInvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Int32 numArgs)
   at System.Windows.Threading.Dispatcher.Invoke(DispatcherPriority priority, Delegate method, Object arg)
   at System.Windows.Interop.HwndSource.OnPreprocessMessageThunk(MSG& msg, Boolean& handled)
   at System.Windows.Interop.HwndSource.WeakEventPreprocessMessage.OnPreprocessMessage(MSG& msg, Boolean& handled)
   at System.Windows.Interop.ThreadMessageEventHandler.Invoke(MSG& msg, Boolean& handled)
   at System.Windows.Interop.ComponentDispatcherThread.RaiseThreadMessage(MSG& msg)
   at System.Windows.Threading.Dispatcher.PushFrameImpl(DispatcherFrame frame)
   at System.Windows.Threading.Dispatcher.PushFrame(DispatcherFrame frame)
   at System.Windows.Application.RunDispatcher(Object ignore)
   at System.Windows.Application.RunInternal(Window window)
   at System.Windows.Application.Run(Window window)
   at System.Windows.Application.Run()
   at WpfApp1.App.Main()

Inner Exception 1:
IscException: Unable to complete network request to host "dbserver".

Inner Exception 2:
SocketException: Este host não é conhecido