diff --git a/services/api-server/src/api_server/html5_ai_structure.py b/services/api-server/src/api_server/html5_ai_structure.py
index 2bbb3c2..58c2761 100644
--- a/services/api-server/src/api_server/html5_ai_structure.py
+++ b/services/api-server/src/api_server/html5_ai_structure.py
@@ -25,6 +25,7 @@ def render_html5_ai_structure_page(*, project_id: str, projects: Iterable[object
             <section class="panel setup-main">
               <div class="panel-title">Подготовка структуры</div>
               {render_html5_ai_structure_form(project_id)}
+              <p class="object-summary">Пути должны быть доступны серверу SFERA/API. Для docker-test используйте папку, смонтированную или доступную внутри контейнера; локальные диски Windows и закрытые SMB-папки без учетных данных сервер не увидит.</p>
               <div data-html5-ai-structure-result>{render_html5_ai_structure_result(result)}</div>
             </section>
           </section>
@@ -43,11 +44,11 @@ def render_html5_ai_structure_form(project_id: str) -> str:
     >
       <label>
         <span>Папка с cf/cfe или выгрузкой</span>
-        <input name="input_path" placeholder="D:\\1c\\source" />
+        <input name="input_path" value="\\\\192.168.220.200\\mst\\1c\\MARKA\\CODEX\\CF" />
       </label>
       <label>
         <span>Папка результата</span>
-        <input name="output_path" placeholder="D:\\sfera-ai\\result" />
+        <input name="output_path" value="\\\\192.168.220.200\\mst\\1c\\MARKA\\CODEX\\CODEX" />
       </label>
       <label>
         <span>Project id</span>
@@ -85,6 +86,21 @@ def render_html5_ai_structure_result(result: dict | None) -> str:
     """
 
 
+def render_html5_ai_structure_error(message: str) -> str:
+    return f"""
+    <section class="ai-structure-result" data-html5-ai-structure-status="error">
+      <div class="access-plan-head">
+        <span class="status-pill">ошибка</span>
+        <strong>Подготовка не выполнена</strong>
+      </div>
+      <ul class="access-warnings">
+        <li>{escape(message)}</li>
+      </ul>
+      <p class="muted padded">Проверьте, что входная и выходная папки доступны именно серверу SFERA/API. Если файлы лежат на рабочем ПК, сначала положите их в общую папку или выполните экспорт через агент.</p>
+    </section>
+    """
+
+
 def _diagnostics(items: list[object]) -> str:
     if not items:
         return ""
diff --git a/services/api-server/src/api_server/html5_ai_structure_controller.py b/services/api-server/src/api_server/html5_ai_structure_controller.py
index 81787d1..e581167 100644
--- a/services/api-server/src/api_server/html5_ai_structure_controller.py
+++ b/services/api-server/src/api_server/html5_ai_structure_controller.py
@@ -6,7 +6,11 @@ from typing import Any
 
 from fastapi import HTTPException
 
-from api_server.html5_ai_structure import render_html5_ai_structure_page, render_html5_ai_structure_result
+from api_server.html5_ai_structure import (
+    render_html5_ai_structure_error,
+    render_html5_ai_structure_page,
+    render_html5_ai_structure_result,
+)
 from api_server.html5_forms import form_value
 
 
@@ -28,8 +32,15 @@ def html5_ai_structure_run(
     input_path = form_value(form, "input_path")
     output_path = form_value(form, "output_path")
     if not input_path:
-        raise HTTPException(status_code=400, detail="input_path is required")
+        return render_html5_ai_structure_error("Заполните входную папку с .cf/.cfe или выгрузкой 1С.")
     if not output_path:
-        raise HTTPException(status_code=400, detail="output_path is required")
-    result = prepare(project_id=effective_project_id, input_path=Path(input_path), output_path=Path(output_path))
+        return render_html5_ai_structure_error("Заполните папку результата.")
+    try:
+        result = prepare(project_id=effective_project_id, input_path=Path(input_path), output_path=Path(output_path))
+    except FileNotFoundError as error:
+        return render_html5_ai_structure_error(str(error))
+    except PermissionError as error:
+        return render_html5_ai_structure_error(f"Нет доступа к папке: {error}")
+    except OSError as error:
+        return render_html5_ai_structure_error(f"Ошибка файловой системы: {error}")
     return render_html5_ai_structure_result(result)
diff --git a/services/api-server/tests/test_api.py b/services/api-server/tests/test_api.py
index 55e009e..6b87b2b 100644
--- a/services/api-server/tests/test_api.py
+++ b/services/api-server/tests/test_api.py
@@ -1727,7 +1727,14 @@ def test_ai_structure_prepare_writes_ai_ready_package(tmp_path: Path):
     assert "Treat modules/forms/commands as parts" in (output / "ai_context.md").read_text(encoding="utf-8")
 
     page = client.get("/html5/projects/ai-demo/ai-structure")
-    assert_html5_response_contract(page, 'data-html5-page="ai-structure"', "Структура для ИИ", full_page=True)
+    assert_html5_response_contract(
+        page,
+        'data-html5-page="ai-structure"',
+        "Структура для ИИ",
+        "192.168.220.200",
+        "Пути должны быть доступны серверу",
+        full_page=True,
+    )
 
     html5_run = client.post(
         "/html5/projects/ai-demo/ai-structure/run",
@@ -1735,6 +1742,12 @@ def test_ai_structure_prepare_writes_ai_ready_package(tmp_path: Path):
     )
     assert_html5_response_contract(html5_run, "ready", "codex-1c-context-ai-demo-html5", "sir_snapshot.json", "normalized_project.json")
 
+    html5_missing = client.post(
+        "/html5/projects/ai-demo/ai-structure/run",
+        data={"project_id": "ai-demo-html5", "input_path": str(tmp_path / "missing"), "output_path": str(tmp_path / "html5-out")},
+    )
+    assert_html5_response_contract(html5_missing, "ошибка", "Input path not found")
+
 
 def test_ai_structure_prepare_reports_cf_cfe_export_required(tmp_path: Path):
     source = tmp_path / "cf-source"