diff --git a/app/crashReports.main.ts b/app/crashReports.main.ts
index dbb14592da..194b086b69 100644
--- a/app/crashReports.main.ts
+++ b/app/crashReports.main.ts
@@ -105,7 +105,8 @@ export function setup(
   showDebugLogWindow: () => Promise<void>,
   forceEnable = false
 ): void {
-  const isEnabled = !isProduction(app.getVersion()) || forceEnable;
+  const isEnabled =
+    (!isProduction(app.getVersion()) || forceEnable) && !process.mas;
 
   if (isEnabled) {
     logger.info(`crashReporter: ${forceEnable ? 'force ' : ''}enabled`);
diff --git a/app/menu.std.ts b/app/menu.std.ts
index 838b797bbc..0f47420e1d 100644
--- a/app/menu.std.ts
+++ b/app/menu.std.ts
@@ -151,7 +151,7 @@ export const createTemplate = (
               },
             ]
           : []),
-        ...(devTools && platform !== 'linux'
+        ...(devTools && platform !== 'linux' && !process.mas
           ? [
               {
                 label: i18n('icu:forceUpdate'),
diff --git a/app/updateDefaultSession.main.ts b/app/updateDefaultSession.main.ts
index 1a0ace16ac..c0980f6d76 100644
--- a/app/updateDefaultSession.main.ts
+++ b/app/updateDefaultSession.main.ts
@@ -28,6 +28,12 @@ export function updateDefaultSession(
         strictAssert(videoRequested, 'Not requesting video');
         strictAssert(!audioRequested, 'Requesting audio');
 
+        // desktopCapturer.getSources()  will crash in the MAS sandbox.
+        // This should never be reached because MAS requires
+        // macOS 15+ where we use @indutny/mac-screen-share directly
+        // and never call getDisplayMedia().
+        strictAssert(!process.mas, 'Unexpected getDisplayMedia() in MAS build');
+
         // macOS: if screen sharing is actively denied, Sonoma will crash
         // when we try to get the sources.
         if (
diff --git a/build/entitlements.mas-dev.plist b/build/entitlements.mas-dev.plist
index 3792692b60..eff52a1624 100644
--- a/build/entitlements.mas-dev.plist
+++ b/build/entitlements.mas-dev.plist
@@ -23,6 +23,8 @@
     <true/>
     <key>com.apple.security.network.client</key>
     <true/>
+    <key>com.apple.security.network.server</key>
+    <true/>
     <key>com.apple.security.application-groups</key>
     <array>
       <string>U68MSDN6DR.org.whispersystems.signal-desktop</string>
diff --git a/package.json b/package.json
index f97e383217..262c6fc19f 100644
--- a/package.json
+++ b/package.json
@@ -480,8 +480,7 @@
       "extendInfo": {
         "ElectronTeamID": "U68MSDN6DR",
         "NSCameraUsageDescription": "Signal uses your camera for video calling.",
-        "NSMicrophoneUsageDescription": "Signal uses your microphone for voice and video calling.",
-        "ITSAppUsesNonExemptEncryption": true
+        "NSMicrophoneUsageDescription": "Signal uses your microphone for voice and video calling."
       }
     },
     "win": {
diff --git a/ts/scripts/prune-macos-release.node.ts b/ts/scripts/prune-macos-release.node.ts
index e412f1bec6..478ceb9210 100644
--- a/ts/scripts/prune-macos-release.node.ts
+++ b/ts/scripts/prune-macos-release.node.ts
@@ -21,7 +21,7 @@ export async function afterPack({
   packager,
   electronPlatformName,
 }: AfterPackContext): Promise<void> {
-  if (electronPlatformName !== 'darwin' && electronPlatformName !== 'mas') {
+  if (electronPlatformName !== 'darwin') {
     return;
   }
 
diff --git a/ts/util/desktopCapturer.preload.ts b/ts/util/desktopCapturer.preload.ts
index a59e95bf44..672734d209 100644
--- a/ts/util/desktopCapturer.preload.ts
+++ b/ts/util/desktopCapturer.preload.ts
@@ -108,6 +108,15 @@ export class DesktopCapturer {
         step: Step.NativeMacOS,
         stream: this.#getNativeMacOSStream(),
       };
+    } else if (process.mas) {
+      // MAS without native ScreenCaptureKit support: desktopCapturer.getSources()
+      // is unavailable in the App Store sandbox. Gracefully report an error.
+      this.#state = { step: Step.Error };
+      options.onError(
+        new Error(
+          'Screen sharing requires macOS 15+ on the Mac App Store version'
+        )
+      );
     } else {
       this.#state = { step: Step.RequestingMedia, promise: this.#getStream() };
     }