diff --git a/src/BreCalClient/MainWindow.xaml.cs b/src/BreCalClient/MainWindow.xaml.cs
index 4d13c6b..f9aaa80 100644
--- a/src/BreCalClient/MainWindow.xaml.cs
+++ b/src/BreCalClient/MainWindow.xaml.cs
@@ -19,6 +19,10 @@ using static BreCalClient.Extensions;
 using System.Collections.Concurrent;
 using Newtonsoft.Json;
 using System.Security.Principal;
+using Polly;
+using System.Net.Http;
+using System.Net;
+using Polly.Retry;
 
 namespace BreCalClient
 {
@@ -34,8 +38,7 @@ namespace BreCalClient
         #region Fields
 
         private static Int32 _uiUpdateRunning = 0;
-
-        private Timer? _timer;
+        
         private Credentials? _credentials;
 
         private readonly ConcurrentDictionary<int, ShipcallControlModel> _allShipcallsDict = new();
@@ -73,7 +76,29 @@ namespace BreCalClient
         {
             InitializeComponent();
             _api = new DefaultApi(Properties.Settings.Default.API_URL);
-            _api.Configuration.ApiKeyPrefix["Authorization"] = "Bearer";            
+            _api.Configuration.ApiKeyPrefix["Authorization"] = "Bearer";
+
+            const int maxDelayInMilliseconds = 32 * 1000;
+            var jitterer = new Random();
+
+            var retryPolicy = 
+                Policy.Handle<HttpRequestException>()
+                .OrResult<RestSharp.RestResponse>(resp => resp.StatusCode == HttpStatusCode.Unauthorized)
+                .WaitAndRetryAsync(3, 
+                retryAttempt =>
+                {
+                    var calculatedDelayInMilliseconds = Math.Pow(2, retryAttempt) * 1000;
+                    var jitterInMilliseconds = jitterer.Next(0, 1000);
+
+                    var actualDelay = Math.Min(calculatedDelayInMilliseconds + jitterInMilliseconds, maxDelayInMilliseconds);
+                    return TimeSpan.FromMilliseconds(actualDelay);
+                },
+                onRetry: (resp, timespan, context) =>
+                {
+                    this.RefreshToken(null);
+                    Trace.WriteLine("token refreshed");
+                });
+            RetryConfiguration.AsyncRetryPolicy = retryPolicy;
         }
 
         #endregion
@@ -123,8 +148,7 @@ namespace BreCalClient
                         this.busyIndicator.IsBusy = false;
                         this._api.Configuration.ApiKey["Authorization"] = _loginResult.Token;
                         this.LoadStaticLists();
-                        this.labelUsername.Text = $"{_loginResult.FirstName} {_loginResult.LastName}";
-                        _timer = new Timer(RefreshToken, null, 4000000, Timeout.Infinite);
+                        this.labelUsername.Text = $"{_loginResult.FirstName} {_loginResult.LastName}";                        
                     }
                 }
                 labelGeneralStatus.Text = $"Connection {ConnectionStatus.SUCCESSFUL}";
@@ -150,8 +174,9 @@ namespace BreCalClient
             }
         }
 
-        private void RefreshToken(object? state)
+        private bool RefreshToken(object? state)
         {
+            bool result = false;
             try
             {
                 _loginResult = _api.LoginPost(_credentials);
@@ -159,7 +184,8 @@ namespace BreCalClient
                 {
                     if (_loginResult.Id > 0)
                     {                        
-                        this._api.Configuration.ApiKey["Authorization"] = _loginResult.Token;                        
+                        this._api.Configuration.ApiKey["Authorization"] = _loginResult.Token;
+                        result = true;
                     }                    
                 }
                 else
@@ -171,6 +197,7 @@ namespace BreCalClient
             {
                 _log.ErrorFormat("Error refreshing token: {0}", ex.Message);
             }
+            return result;
         }
 
         private void buttonExit_Click(object sender, RoutedEventArgs e)
@@ -805,10 +832,13 @@ namespace BreCalClient
 
         private void ShowErrorDialog(string message, string caption)
         {
+            _log.ErrorFormat("{0} - {1}", caption, message);
+            /*
             Dispatcher.Invoke(new Action(() =>
             {
                 MessageBox.Show(message, caption, MessageBoxButton.OK, MessageBoxImage.Error);
-            }));            
+            }));
+            */
         }
 
         private void EnableControlsForParticipant()