diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8b43e33..6a5f2b2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,13 @@
 
 All notable changes to Multi-Debrid Downloader are documented in this file.
 
+## [2.0.27] - 2026-08-12
+
+### Startup reliability
+
+- Fixed Windows renderer startup validation so the packaged application accepts its own local renderer path regardless of path casing.
+- Prevented the startup navigation guard from blocking the application window on case-insensitive Windows file systems.
+
 ## [2.0.26] - 2026-08-12
 
 ### Log storage
diff --git a/package-lock.json b/package-lock.json
index 3e44f53..20f1fa4 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "real-debrid-downloader",
-  "version": "2.0.26",
+  "version": "2.0.27",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "real-debrid-downloader",
-      "version": "2.0.26",
+      "version": "2.0.27",
       "license": "MIT",
       "dependencies": {
         "adm-zip": "0.6.0",
diff --git a/package.json b/package.json
index 5d06119..009cf84 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "real-debrid-downloader",
-  "version": "2.0.26",
+  "version": "2.0.27",
   "description": "Desktop downloader",
   "main": "build/main/main/main.js",
   "author": "Sucukdeluxe",
diff --git a/src/main/browser-security.ts b/src/main/browser-security.ts
index c3241e7..be7ac8a 100644
--- a/src/main/browser-security.ts
+++ b/src/main/browser-security.ts
@@ -1,3 +1,5 @@
+import path from "node:path";
+import { fileURLToPath } from "node:url";
 import { shell, type WebPreferences } from "electron";
 
 export type HttpsHostRule = {
@@ -144,7 +146,14 @@ function isExpectedRendererUrl(rawUrl: string, expectedUrl: string): boolean {
     const parsed = new URL(String(rawUrl || ""));
     const expected = new URL(String(expectedUrl || ""));
     if (expected.protocol === "file:") {
-      return parsed.protocol === "file:" && parsed.host === expected.host && parsed.pathname === expected.pathname;
+      if (parsed.protocol !== "file:") {
+        return false;
+      }
+      const actualPath = path.resolve(fileURLToPath(parsed));
+      const expectedPath = path.resolve(fileURLToPath(expected));
+      return process.platform === "win32"
+        ? actualPath.toLowerCase() === expectedPath.toLowerCase()
+        : actualPath === expectedPath;
     }
     return parsed.origin === expected.origin;
   } catch {
diff --git a/tests/browser-security.test.ts b/tests/browser-security.test.ts
index ad8f8c3..b3637c8 100644
--- a/tests/browser-security.test.ts
+++ b/tests/browser-security.test.ts
@@ -157,6 +157,19 @@ describe("browser-security", () => {
     expect(attacker.preventDefault).toHaveBeenCalledTimes(1);
   });
 
+  it("allows the packaged renderer file despite Windows path casing differences", () => {
+    const harness = createWindow();
+    const rendererUrl = "file:///C:/Program%20Files/MDD/resources/app.asar/build/renderer/index.html";
+    applyMainWindowSecurity(harness.window, {
+      rendererUrl,
+      externalHosts: githubOnly
+    });
+
+    const renderer = harness.navigate("file:///c:/program%20files/mdd/resources/app.asar/build/renderer/index.html");
+
+    expect(renderer.preventDefault).not.toHaveBeenCalled();
+  });
+
   it("denies popups while allowing exact allowlisted HTTPS popup URLs through the shell", () => {
     const harness = createWindow();
     applyMainWindowSecurity(harness.window, {