DSharpPlus
diff --git a/DSharpPlus/Clients/MultiShardOrchestrator.cs b/DSharpPlus/Clients/MultiShardOrchestrator.cs
@@ -2,6 +2,7 @@
 using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Linq;
+using System.Threading.RateLimiting;
 using System.Threading.Tasks;
 
 using DSharpPlus.Entities;
@@ -27,6 +28,7 @@ public sealed class MultiShardOrchestrator : IShardOrchestrator
     private readonly IServiceProvider serviceProvider;
     private readonly IPayloadDecompressor decompressor;
     private readonly ILogger<IShardOrchestrator> logger;
+    private readonly ConcurrencyLimiter reconnectConcurrencyLimiter;
 
     private uint shardCount;
     private uint stride;
@@ -67,6 +69,12 @@ ILogger<IShardOrchestrator> logger
         this.serviceProvider = serviceProvider;
         this.decompressor = decompressor;
         this.logger = logger;
+
+        this.reconnectConcurrencyLimiter = new(new()
+        {
+            PermitLimit = 1,
+            QueueLimit = int.MaxValue
+        });
     }
 
     /// <inheritdoc/>
@@ -251,6 +259,7 @@ private async Task RunGatewayAsync(int shardNumber, string uri, DiscordActivity?
                 break;
             }
 
+            using RateLimitLease lease = await this.reconnectConcurrencyLimiter.AcquireAsync();
             gatewayTask = this.shards[shardNumber].ReconnectAsync();
         }
     }

diff --git a/DSharpPlus/Exceptions/InvalidGatewayStateException.cs b/DSharpPlus/Exceptions/InvalidGatewayStateException.cs
@@ -0,0 +1,8 @@
+using System;
+
+namespace DSharpPlus.Exceptions;
+
+/// <summary>
+/// Indicates that the gateway has entered an invalid state and must reconnect.
+/// </summary>
+public sealed class InvalidGatewayStateException(string message) : Exception(message);
diff --git a/DSharpPlus/Net/Gateway/GatewayClient.cs b/DSharpPlus/Net/Gateway/GatewayClient.cs
@@ -11,6 +11,7 @@
 using System.Threading.Tasks;
 
 using DSharpPlus.Entities;
+using DSharpPlus.Exceptions;
 using DSharpPlus.Net.Abstractions;
 using DSharpPlus.Net.Gateway.Compression;
 using DSharpPlus.Net.Serialization;
@@ -328,6 +329,8 @@ await WriteAsync
     /// </summary>
     private async Task HandleEventsAsync(CancellationToken ct)
     {
+        int consecutiveInvalidEvents = 0;
+
         try
         {
             while (!ct.IsCancellationRequested)
@@ -344,7 +347,30 @@ private async Task HandleEventsAsync(CancellationToken ct)
                     continue;
                 }
 
-                GatewayPayload? payload = await ProcessAndDeserializeTransportFrameAsync(frame);
+                GatewayPayload? payload = null;
+
+                try
+                {
+                    payload = await ProcessAndDeserializeTransportFrameAsync(frame);
+                    consecutiveInvalidEvents = 0;
+                }
+                catch (JsonException)
+                {
+                    if (frame.TryGetMessage(out byte[]? message))
+                    {
+                        this.logger.LogError("Received undeserializable gateway payload: {payload}", Encoding.UTF8.GetString(message));
+                        consecutiveInvalidEvents++;
+                    }
+                    else
+                    {
+                        throw;
+                    }
+
+                    if (consecutiveInvalidEvents > 5)
+                    {
+                        throw new InvalidGatewayStateException("Received over five consecutive invalid events, the connection likely entered an invalid state and should reconnect.");
+                    }
+                }
 
                 if (payload is null)
                 {
@@ -363,7 +389,8 @@ private async Task HandleEventsAsync(CancellationToken ct)
         }
     }
 
-    private async Task HandleEventCoreAsync(GatewayPayload payload)
+    [AsyncMethodBuilder(typeof(PoolingAsyncValueTaskMethodBuilder))]
+    private async ValueTask HandleEventCoreAsync(GatewayPayload payload)
     {
         switch (payload.OpCode)
         {
@@ -451,7 +478,7 @@ private async Task HandleEventCoreAsync(GatewayPayload payload)
     /// </summary>
     private async Task<bool> TryResumeAsync()
     {
-        if (this.resumeUrl is null || this.sessionId is null)
+        if (this.resumeUrl is null || this.sessionId is null || !this.IsConnected)
         {
             return false;
         }
@@ -581,7 +608,7 @@ private async Task HandleErrorAndAttemptToResumeAsync(TransportFrame frame)
             bool success = errorCode switch
             {
                 < 4000 => await HandleSystemErrorAsync(errorCode),
-                (>= 4000 and <= 4002) or 4005 or 4008 => await TryResumeAsync(),
+                (>= 4000 and <= 4002) or 4005 or 4008 or 5000 => await TryResumeAsync(),
                 _ => false
             };
 

diff --git a/DSharpPlus/Net/Gateway/TransportService.cs b/DSharpPlus/Net/Gateway/TransportService.cs
@@ -125,6 +125,7 @@ await this.socket.CloseAsync
                 }
                 catch (WebSocketException) { }
                 catch (OperationCanceledException) { }
+                catch (InvalidOperationException) { }
 
                 break;
         }
@@ -167,6 +168,11 @@ public async ValueTask<TransportFrame> ReadAsync()
 
         this.metrics.RecordGatewayEventReceived(this.writer.WrittenCount);
 
+        if (this.socket.CloseStatus is not null || this.writer.WrittenCount == 0)
+        {
+            return new(((int?)this.socket.CloseStatus) ?? 5000, WebSocketMessageType.Close);
+        }
+
         if (!this.decompressor.TryDecompress(this.writer.WrittenSpan, this.decompressedWriter))
         {
             throw new InvalidDataException("Failed to decompress a gateway payload.");