From 33a975b9075980d03430a65ab26571ce64d58f6d Mon Sep 17 00:00:00 2001
From: Copilot <198982749+Copilot@users.noreply.github.com>
Date: Thu, 1 Jan 2026 21:19:59 +0200
Subject: [PATCH] Fix case-insensitive lookup for data package index file
 (#1460)

Co-authored-by: Tyrrrz <1935960+Tyrrrz@users.noreply.github.com>
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
---
 .gitignore                                        | 2 +-
 DiscordChatExporter.Core/Discord/Dump/DataDump.cs | 9 ++++++++-
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/.gitignore b/.gitignore
index ef8150c0..20d4f315 100644
--- a/.gitignore
+++ b/.gitignore
@@ -9,4 +9,4 @@ bin/
 obj/
 
 # Test results
-TestResults/
\ No newline at end of file
+TestResults/
diff --git a/DiscordChatExporter.Core/Discord/Dump/DataDump.cs b/DiscordChatExporter.Core/Discord/Dump/DataDump.cs
index be3deb1c..10a4832c 100644
--- a/DiscordChatExporter.Core/Discord/Dump/DataDump.cs
+++ b/DiscordChatExporter.Core/Discord/Dump/DataDump.cs
@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.IO.Compression;
+using System.Linq;
 using System.Text.Json;
 using System.Threading;
 using System.Threading.Tasks;
@@ -42,7 +43,13 @@ public partial class DataDump
     {
         using var archive = ZipFile.OpenRead(zipFilePath);
 
-        var entry = archive.GetEntry("messages/index.json");
+        // Try to find the index file with case-insensitive search
+        // Discord changed the structure from "messages/index.json" to "Messages/index.json"
+        // https://github.com/Tyrrrz/DiscordChatExporter/issues/1458
+        var entry = archive.Entries.FirstOrDefault(e =>
+            e.FullName.Equals("messages/index.json", StringComparison.OrdinalIgnoreCase)
+        );
+
         if (entry is null)
         {
             throw new InvalidOperationException(