diff --git a/core/models/database.py b/core/models/database.py
index 15327ea..936c26b 100644
--- a/core/models/database.py
+++ b/core/models/database.py
@@ -22,6 +22,7 @@ def init_db(app):
         from . import qc_report
         from . import usage_log
         from . import campaign_presentation
+        from core.utils.progress_tracker import ProgressSession  # noqa: F401
 
         # Create all tables (if they don't exist)
         # Tables are created automatically on first access
diff --git a/core/utils/progress_tracker.py b/core/utils/progress_tracker.py
index 1532734..bc37efb 100644
--- a/core/utils/progress_tracker.py
+++ b/core/utils/progress_tracker.py
@@ -8,7 +8,6 @@ import json
 import time
 from datetime import datetime
 from typing import Optional, Dict, Any
-from flask import session
 from core.models.database import db
 
 
diff --git a/modules/hm_qc/batch_executor.py b/modules/hm_qc/batch_executor.py
index 6b8806f..c59e0b2 100644
--- a/modules/hm_qc/batch_executor.py
+++ b/modules/hm_qc/batch_executor.py
@@ -37,7 +37,8 @@ class BatchQCExecutor:
         job_number: str = None,
         batch_size: int = DEFAULT_BATCH_SIZE,
         campaign_id: str = None,
-        batch_id: str = None
+        batch_id: str = None,
+        app=None
     ):
         """
         Initialize batch executor.
@@ -50,6 +51,7 @@ class BatchQCExecutor:
             batch_size: Number of files per batch (default 10)
             campaign_id: Optional campaign ID to load presentation guidelines
             batch_id: Optional batch ID for grouping reports from the same upload
+            app: Flask app instance (required for ThreadPoolExecutor child threads)
         """
         self.session_id = session_id
         self.file_paths = file_paths[:MAX_FILES]
@@ -58,6 +60,7 @@ class BatchQCExecutor:
         self.campaign_id = campaign_id
         self.batch_id = batch_id
         self.batch_size = batch_size
+        self.app = app
         self.progress = UnifiedProgressTracker(session_id)
         self.results = []
 
@@ -165,6 +168,9 @@ class BatchQCExecutor:
         """
         Process a single file using QCExecutor.
 
+        Runs inside a ThreadPoolExecutor child thread, so we must push
+        an app context explicitly (child threads don't inherit it).
+
         Errors are captured and returned, not raised.
 
         Args:
@@ -177,31 +183,32 @@ class BatchQCExecutor:
         """
         filename = os.path.basename(file_path)
         try:
-            # Create a per-file executor with a sub-session ID
-            # We don't use its progress tracker—we track at the batch level
-            file_session_id = f"{self.session_id}_file_{completed}"
+            with self.app.app_context():
+                # Create a per-file executor with a sub-session ID
+                # We don't use its progress tracker—we track at the batch level
+                file_session_id = f"{self.session_id}_file_{completed}"
 
-            executor = QCExecutor(
-                session_id=file_session_id,
-                file_path=file_path,
-                profile=self.profile,
-                job_number=self.job_number,
-                campaign_id=self.campaign_id,
-                batch_id=self.batch_id
-            )
+                executor = QCExecutor(
+                    session_id=file_session_id,
+                    file_path=file_path,
+                    profile=self.profile,
+                    job_number=self.job_number,
+                    campaign_id=self.campaign_id,
+                    batch_id=self.batch_id
+                )
 
-            result = executor.execute()
+                result = executor.execute()
 
-            return {
-                'filename': filename,
-                'file_path': file_path,
-                'success': result.get('success', False),
-                'score': result.get('overall_score'),
-                'status': result.get('overall_status', 'error'),
-                'report_path': result.get('report_path'),
-                'report_id': result.get('report_id'),
-                'error': result.get('error')
-            }
+                return {
+                    'filename': filename,
+                    'file_path': file_path,
+                    'success': result.get('success', False),
+                    'score': result.get('overall_score'),
+                    'status': result.get('overall_status', 'error'),
+                    'report_path': result.get('report_path'),
+                    'report_id': result.get('report_id'),
+                    'error': result.get('error')
+                }
 
         except Exception as e:
             logger.error(f"Error processing file {filename}: {e}")
diff --git a/modules/hm_qc/routes.py b/modules/hm_qc/routes.py
index fbf0cde..6cb5708 100644
--- a/modules/hm_qc/routes.py
+++ b/modules/hm_qc/routes.py
@@ -317,17 +317,18 @@ def execute_batch():
         campaign_id = data.get('campaign_id')
         batch_id = str(uuid.uuid4())
 
+        app = current_app._get_current_object()
+
         batch_executor = BatchQCExecutor(
             session_id=session_id,
             file_paths=file_paths,
             profile=profile,
             job_number=job_number,
             campaign_id=campaign_id,
-            batch_id=batch_id
+            batch_id=batch_id,
+            app=app
         )
 
-        app = current_app._get_current_object()
-
         def run_batch():
             with app.app_context():
                 result = batch_executor.execute()