From 2ba33ec2ef246153d33c7bfccc3cd5807d22a001 Mon Sep 17 00:00:00 2001
From: LotP <22-lotp@users.noreply.git.ryujinx.app>
Date: Sat, 6 Dec 2025 20:16:43 -0600
Subject: [PATCH] Fix kaddressarbiter crash

Fixes a crash when trying to access the thread count on a not (yet) existing list of threads.
---
 src/Ryujinx.HLE/HOS/Kernel/Threading/KAddressArbiter.cs | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/Ryujinx.HLE/HOS/Kernel/Threading/KAddressArbiter.cs b/src/Ryujinx.HLE/HOS/Kernel/Threading/KAddressArbiter.cs
index 3e13b917a..8b339eabc 100644
--- a/src/Ryujinx.HLE/HOS/Kernel/Threading/KAddressArbiter.cs
+++ b/src/Ryujinx.HLE/HOS/Kernel/Threading/KAddressArbiter.cs
@@ -529,7 +529,12 @@ namespace Ryujinx.HLE.HOS.Kernel.Threading
             // The value is decremented if the number of threads waiting is less
             // or equal to the Count of threads to be signaled, or Count is zero
             // or negative. It is incremented if there are no threads waiting.
-            int waitingCount = _arbiterThreads[address].Count;
+            int waitingCount = 0;
+
+            if (_arbiterThreads.TryGetValue(address, out List<KThread> threads))
+            {
+                waitingCount = threads.Count;
+            }
 
             if (waitingCount > 0)
             {