diff --git a/Dockerfile b/Dockerfile
index 906c6c2..6b88ac4 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -24,11 +24,7 @@ COPY README.md .
 RUN mkdir cache user_agents scraped
 
 RUN echo LOOKYLOO_HOME="'`pwd`'" > .env
-RUN cp config/generic.json.sample config/generic.json
-RUN cp config/modules.json.sample config/modules.json
 RUN poetry install
 RUN poetry run playwright install
-RUN poetry run tools/validate_config_files.py --check
-RUN poetry run tools/validate_config_files.py --update
 RUN poetry run tools/3rdparty.py
 RUN poetry run tools/generate_sri.py
diff --git a/bin/async_capture.py b/bin/async_capture.py
index 8adce4c..96f359b 100755
--- a/bin/async_capture.py
+++ b/bin/async_capture.py
@@ -179,7 +179,7 @@ class AsyncCapture(AbstractManager):
         if 'error' in entries:
             with (dirpath / 'error.txt').open('w') as _error:
                 json.dump(entries['error'], _error)
-            return False, entries['error']
+            return False, entries['error'] if entries['error'] else "Unknown error"
 
         # The capture went fine
         harfile = entries['har']