diff --git a/Reactor.Greenhouse/Program.cs b/Reactor.Greenhouse/Program.cs
index 744d047..616d7e4 100644
--- a/Reactor.Greenhouse/Program.cs
+++ b/Reactor.Greenhouse/Program.cs
@@ -11,6 +11,7 @@ using Mono.Cecil;
 using Newtonsoft.Json;
 using Newtonsoft.Json.Serialization;
 using Reactor.Greenhouse.Setup;
+using Reactor.Greenhouse.Setup.Provider;
 using Reactor.OxygenFilter;
 
 namespace Reactor.Greenhouse
@@ -33,6 +34,7 @@ namespace Reactor.Greenhouse
         public static async Task GenerateAsync(bool steam, bool itch)
         {
             var gameManager = new GameManager();
+
             await gameManager.SetupAsync(steam, itch);
 
             JsonConvert.DefaultSettings = () => new JsonSerializerSettings
@@ -46,6 +48,12 @@ namespace Reactor.Greenhouse
             Console.WriteLine($"Generating mappings from {gameManager.PreObfuscation.Name} ({gameManager.PreObfuscation.Version})");
             using var old = ModuleDefinition.ReadModule(File.OpenRead(gameManager.PreObfuscation.Dll));
 
+            if (!steam && !itch)
+            {
+                Console.WriteLine("No game providers used! (use --help for more info)");
+                return;
+            }
+
             if (steam)
             {
                 await GenerateAsync(gameManager.Steam, old);
diff --git a/Reactor.Greenhouse/Setup/Provider/BaseProvider.cs b/Reactor.Greenhouse/Setup/Provider/BaseProvider.cs
index b552ab7..5c72ef5 100644
--- a/Reactor.Greenhouse/Setup/Provider/BaseProvider.cs
+++ b/Reactor.Greenhouse/Setup/Provider/BaseProvider.cs
@@ -1,3 +1,4 @@
+using System;
 using System.Threading.Tasks;
 
 namespace Reactor.Greenhouse.Setup.Provider
@@ -10,4 +11,14 @@ namespace Reactor.Greenhouse.Setup.Provider
         public abstract Task DownloadAsync();
         public abstract bool IsUpdateNeeded();
     }
+
+    public class ProviderConnectionException : Exception
+    {
+        public BaseProvider Provider { get; }
+
+        public ProviderConnectionException(BaseProvider provider, string message) : base(message)
+        {
+            Provider = provider;
+        }
+    }
 }
diff --git a/Reactor.Greenhouse/Setup/Provider/ItchProvider.cs b/Reactor.Greenhouse/Setup/Provider/ItchProvider.cs
index 4d3144c..e56d5aa 100644
--- a/Reactor.Greenhouse/Setup/Provider/ItchProvider.cs
+++ b/Reactor.Greenhouse/Setup/Provider/ItchProvider.cs
@@ -41,7 +41,6 @@ namespace Reactor.Greenhouse.Setup.Provider
 
                 Console.Write("itch.io password: ");
                 Password = Util.ReadPassword();
-
                 Console.WriteLine();
             }
         }
@@ -63,7 +62,7 @@ namespace Reactor.Greenhouse.Setup.Provider
 
             if (!loginResponse.IsSuccessStatusCode || (await loginResponse.Content.ReadAsStringAsync()).Contains("Errors"))
             {
-                throw new Exception("itch.io authentication failed");
+                throw new ProviderConnectionException(this, "Authentication failed");
             }
 
             Console.WriteLine("Logged into itch.io");
diff --git a/Reactor.Greenhouse/Setup/Provider/SteamProvider.cs b/Reactor.Greenhouse/Setup/Provider/SteamProvider.cs
index 543e323..6efbe84 100644
--- a/Reactor.Greenhouse/Setup/Provider/SteamProvider.cs
+++ b/Reactor.Greenhouse/Setup/Provider/SteamProvider.cs
@@ -67,7 +67,10 @@ namespace Reactor.Greenhouse.Setup.Provider
             if (environmentVariable != null)
             {
                 var split = environmentVariable.Split(":");
-                ContentDownloader.InitializeSteam3(split[0], split[1]);
+                if (!ContentDownloader.InitializeSteam3(split[0], split[1]))
+                {
+                    throw new ProviderConnectionException(this, "Incorrect credentials.");
+                }
             }
             else
             {
@@ -85,7 +88,15 @@ namespace Reactor.Greenhouse.Setup.Provider
                     Console.WriteLine();
                 }
 
-                ContentDownloader.InitializeSteam3(username, password);
+                if (!ContentDownloader.InitializeSteam3(username, password))
+                {
+                    throw new ProviderConnectionException(this, "Incorrect credentials.");
+                }
+            }
+
+            if (ContentDownloader.steam3 == null || !ContentDownloader.steam3.bConnected)
+            {
+                throw new ProviderConnectionException(this, "Unable to initialize Steam3 session.");
             }
 
             ContentDownloader.Config.UsingFileList = true;