diff --git a/apps/desktop-shell/scripts/check-config.mjs b/apps/desktop-shell/scripts/check-config.mjs
index 774e8fe1c..07cc4e252 100644
--- a/apps/desktop-shell/scripts/check-config.mjs
+++ b/apps/desktop-shell/scripts/check-config.mjs
@@ -1086,6 +1086,20 @@ function assertDesktopDialogBoundary(method, functionName, filterLabel, expected
   if (fileFunctionBody.includes(blockedDialogAction)) {
     throw new Error(`desktop shell ${method} must not use ${blockedDialogAction}`);
   }
+  const unavailableResponse =
+    action === 'save'
+      ? 'Err(_) => return file_export_unavailable_response(request)'
+      : 'Err(_) => return file_import_unavailable_response(request)';
+  if (!fileFunctionBody.includes(unavailableResponse)) {
+    throw new Error(`desktop shell ${method} must hide native path conversion errors`);
+  }
+  if (
+    fileFunctionBody.includes(
+      'return failed(request.id.clone(), "host_error", error.to_string())',
+    )
+  ) {
+    throw new Error(`desktop shell ${method} must not expose native path errors`);
+  }
 }
 
 function assertNoRawHostContextUrl(urlValue, label) {
diff --git a/apps/desktop-shell/src-tauri/src/host_bridge/files.rs b/apps/desktop-shell/src-tauri/src/host_bridge/files.rs
index c63f15273..a18ce3496 100644
--- a/apps/desktop-shell/src-tauri/src/host_bridge/files.rs
+++ b/apps/desktop-shell/src-tauri/src/host_bridge/files.rs
@@ -50,7 +50,7 @@ pub(crate) async fn export_desktop_host_bridge_text_file(
     };
     let path = match file_path.into_path() {
         Ok(path) => path,
-        Err(error) => return failed(request.id.clone(), "host_error", error.to_string()),
+        Err(_) => return file_export_unavailable_response(request),
     };
     let export_result =
         tauri::async_runtime::spawn_blocking(move || write_export_text_file(path, content)).await;
@@ -83,7 +83,7 @@ pub(crate) async fn import_desktop_host_bridge_text_file(
     };
     let path = match file_path.into_path() {
         Ok(path) => path,
-        Err(error) => return failed(request.id.clone(), "host_error", error.to_string()),
+        Err(_) => return file_import_unavailable_response(request),
     };
     let import_result =
         tauri::async_runtime::spawn_blocking(move || import_text_file_payload(path)).await;
@@ -111,7 +111,7 @@ pub(crate) async fn import_desktop_host_bridge_document_file(
     };
     let path = match file_path.into_path() {
         Ok(path) => path,
-        Err(error) => return failed(request.id.clone(), "host_error", error.to_string()),
+        Err(_) => return file_import_unavailable_response(request),
     };
     let import_result =
         tauri::async_runtime::spawn_blocking(move || import_document_file_payload(path)).await;
@@ -141,7 +141,7 @@ pub(crate) async fn export_desktop_host_bridge_image_file(
     };
     let path = match file_path.into_path() {
         Ok(path) => path,
-        Err(error) => return failed(request.id.clone(), "host_error", error.to_string()),
+        Err(_) => return file_export_unavailable_response(request),
     };
     let export_result =
         tauri::async_runtime::spawn_blocking(move || write_export_bytes_file(path, bytes)).await;
@@ -173,7 +173,7 @@ pub(crate) async fn import_desktop_host_bridge_image_file(
     };
     let path = match file_path.into_path() {
         Ok(path) => path,
-        Err(error) => return failed(request.id.clone(), "host_error", error.to_string()),
+        Err(_) => return file_import_unavailable_response(request),
     };
     let import_result = tauri::async_runtime::spawn_blocking(move || {
         import_image_file_payload(path, "selected", None)
@@ -200,7 +200,7 @@ pub(crate) async fn import_desktop_host_bridge_audio_file(
     };
     let path = match file_path.into_path() {
         Ok(path) => path,
-        Err(error) => return failed(request.id.clone(), "host_error", error.to_string()),
+        Err(_) => return file_import_unavailable_response(request),
     };
     let import_result =
         tauri::async_runtime::spawn_blocking(move || import_audio_file_payload(path)).await;
@@ -230,7 +230,7 @@ pub(crate) async fn export_desktop_host_bridge_audio_file(
     };
     let path = match file_path.into_path() {
         Ok(path) => path,
-        Err(error) => return failed(request.id.clone(), "host_error", error.to_string()),
+        Err(_) => return file_export_unavailable_response(request),
     };
     let export_result =
         tauri::async_runtime::spawn_blocking(move || write_export_bytes_file(path, bytes)).await;