diff --git a/services/web/server/src/simcore_service_webserver/exception_handling/_factory.py b/services/web/server/src/simcore_service_webserver/exception_handling/_factory.py
index 29abf093cd0..29e3e325117 100644
--- a/services/web/server/src/simcore_service_webserver/exception_handling/_factory.py
+++ b/services/web/server/src/simcore_service_webserver/exception_handling/_factory.py
@@ -14,9 +14,9 @@
 _logger = logging.getLogger(__name__)
 
 
-_STATUS_CODE_TO_HTTP_ERRORS: dict[
-    int, type[web.HTTPError]
-] = get_all_aiohttp_http_exceptions(web.HTTPError)
+_STATUS_CODE_TO_HTTP_ERRORS: dict[int, type[web.HTTPError]] = (
+    get_all_aiohttp_http_exceptions(web.HTTPError)
+)
 
 
 class _DefaultDict(dict):
@@ -40,7 +40,8 @@ def create_error_response(error: ErrorGet, status_code: int) -> web.Response:
     return web.json_response(
         data={"error": error.model_dump(exclude_unset=True, mode="json")},
         dumps=json_dumps,
-        reason=error.message,
+        # NOTE: Multiline not allowed in HTTP reason attribute (aiohttp now raises ValueError)
+        reason=error.message.replace("\n", " ") if error.message else None,
         status=status_code,
     )
 
diff --git a/services/web/server/src/simcore_service_webserver/exporter/exceptions.py b/services/web/server/src/simcore_service_webserver/exporter/exceptions.py
index 66f0833985b..baeff42bead 100644
--- a/services/web/server/src/simcore_service_webserver/exporter/exceptions.py
+++ b/services/web/server/src/simcore_service_webserver/exporter/exceptions.py
@@ -6,4 +6,5 @@ class SDSException(HTTPBadRequest):  # pylint: disable=too-many-ancestors
     """Basic exception for errors raised inside the module"""
 
     def __init__(self, message: str):
-        super().__init__(reason=message)
+        # Multiline not allowed in HTTP reason attribute
+        super().__init__(reason=message.replace("\n", " ") if message else None)