diff --git a/CallbackHandler/Program.cs b/CallbackHandler/Program.cs
index f4dccb4..861c18c 100644
--- a/CallbackHandler/Program.cs
+++ b/CallbackHandler/Program.cs
@@ -70,31 +70,49 @@ public static IHostBuilder CreateHostBuilder(string[] args)
                                          });
             hostBuilder.ConfigureWebHostDefaults(webBuilder =>
                                                  {
-                                                     webBuilder.UseStartup<Startup>();
-                                                     webBuilder.UseConfiguration(config);
-                                                     webBuilder.UseKestrel();
-
-                                                     IConfigurationSection isSentryConfigured = config.GetSection("SentryConfiguration");
-                                                     if (isSentryConfigured.Exists()) {
-                                                         webBuilder.Configure((context,
-                                                                               app) => {
-                                                             if (context.HostingEnvironment.IsDevelopment() == false) {
-                                                                 Version version = Assembly.GetExecutingAssembly().GetName().Version;
-
-                                                                 webBuilder.UseSentry(o => {
-
-                                                                     o.Dsn = ConfigurationReader.GetValueFromSection<String>("SentryConfiguration", "Dsn");
-                                                                     o.SendDefaultPii = true; // required for body + user data
+                                                     // Configure per-environment configuration and build a snapshot so we can read settings here.
+                                                     webBuilder.ConfigureAppConfiguration((context, configBuilder) =>
+                                                     {
+                                                         var env = context.HostingEnvironment;
+
+                                                         configBuilder.SetBasePath(fi.Directory.FullName)
+                                                             .AddJsonFile("hosting.json", optional: true)
+                                                             .AddJsonFile($"hosting.{env.EnvironmentName}.json", optional: true)
+                                                             .AddJsonFile("/home/txnproc/config/appsettings.json", optional: true, reloadOnChange: true)
+                                                             .AddJsonFile($"/home/txnproc/config/appsettings.{env.EnvironmentName}.json", optional: true, reloadOnChange: true)
+                                                             .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)
+                                                             .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true, reloadOnChange: true)
+                                                             .AddEnvironmentVariables();
+
+                                                         // Build a snapshot of configuration so we can use it immediately (e.g. for Sentry)
+                                                         var builtConfig = configBuilder.Build();
+
+                                                         // Keep existing static usage (if you must), and initialise the ConfigurationReader now.
+                                                         Startup.Configuration = builtConfig;
+                                                         ConfigurationReader.Initialise(Startup.Configuration);
+
+                                                         // Configure Sentry on the webBuilder using the config snapshot.
+                                                         var sentrySection = builtConfig.GetSection("SentryConfiguration");
+                                                         if (sentrySection.Exists())
+                                                         {
+                                                             // Replace the condition below if you intended to only enable Sentry in certain environments.
+                                                             if (env.IsDevelopment() == false)
+                                                             {
+                                                                 webBuilder.UseSentry(o =>
+                                                                 {
+                                                                     o.Dsn = builtConfig["SentryConfiguration:Dsn"];
+                                                                     o.SendDefaultPii = true;
                                                                      o.MaxRequestBodySize = RequestSize.Always;
                                                                      o.CaptureBlockingCalls = true;
-                                                                     //o.CaptureFailedRequests = true;
-                                                                     o.Release = version != null ? version.ToString() : "unknown";
-
+                                                                     o.Release = Assembly.GetExecutingAssembly().GetName().Version?.ToString() ?? "unknown";
                                                                  });
                                                              }
-                                                         });
+                                                         }
+                                                     });
 
-                                                     }
+                                                     webBuilder.UseStartup<Startup>();
+                                                     webBuilder.UseConfiguration(config);
+                                                     webBuilder.UseKestrel();
                                                  });
 
             return hostBuilder;
diff --git a/CallbackHandler/Startup.cs b/CallbackHandler/Startup.cs
index 238832d..4fa8feb 100644
--- a/CallbackHandler/Startup.cs
+++ b/CallbackHandler/Startup.cs
@@ -25,14 +25,14 @@ public class Startup
     {
         public Startup(IWebHostEnvironment webHostEnvironment)
         {
-            IConfigurationBuilder builder = new ConfigurationBuilder().SetBasePath(webHostEnvironment.ContentRootPath)
-                                                                      .AddJsonFile("/home/txnproc/config/appsettings.json", true, true)
-                                                                      .AddJsonFile($"/home/txnproc/config/appsettings.{webHostEnvironment.EnvironmentName}.json", optional: true)
-                                                                      .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)
-                                                                      .AddJsonFile($"appsettings.{webHostEnvironment.EnvironmentName}.json", optional: true, reloadOnChange: true)
-                                                                      .AddEnvironmentVariables();
+            //IConfigurationBuilder builder = new ConfigurationBuilder().SetBasePath(webHostEnvironment.ContentRootPath)
+            //                                                          .AddJsonFile("/home/txnproc/config/appsettings.json", true, true)
+            //                                                          .AddJsonFile($"/home/txnproc/config/appsettings.{webHostEnvironment.EnvironmentName}.json", optional: true)
+            //                                                          .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)
+            //                                                          .AddJsonFile($"appsettings.{webHostEnvironment.EnvironmentName}.json", optional: true, reloadOnChange: true)
+            //                                                          .AddEnvironmentVariables();
 
-            Startup.Configuration = builder.Build();
+            //Startup.Configuration = builder.Build();
             Startup.WebHostEnvironment = webHostEnvironment;
         }
 
@@ -109,7 +109,6 @@ public void Configure(IApplicationBuilder app, IWebHostEnvironment env, ILoggerF
             app.UseSwagger();
 
             app.UseSwaggerUI();
-            
         }
     }
 }