diff --git a/marketplaces/ozon.py b/marketplaces/ozon.py
index 677f764..65cee9c 100644
--- a/marketplaces/ozon.py
+++ b/marketplaces/ozon.py
@@ -13,7 +13,13 @@ class OzonMarketplaceApi(BaseMarketplaceApi):
 
     def __init__(self, marketplace: Marketplace):
         self.marketplace = marketplace
-        auth_data = json.loads(marketplace.auth_data)
+        self.is_valid = True
+        try:
+            auth_data = json.loads(marketplace.auth_data)
+        except Exception:
+            logging.error(f"Couldn't load auth data for marketplace [{self.marketplace.id}]")
+            self.is_valid = False
+            return
         client_id = auth_data.get('clientId')
 
         self.limiter_key = str(marketplace.company_id) + str(client_id)
@@ -32,6 +38,8 @@ class OzonMarketplaceApi(BaseMarketplaceApi):
     async def update_stocks(self, data: Union[list, dict]):
         if type(data) is not list:
             return
+        if not self.is_valid:
+            return
         max_stocks = 100
         chunks = utils.chunk_list(data, max_stocks)
         limiter = BatchLimiter()
@@ -49,7 +57,7 @@ class OzonMarketplaceApi(BaseMarketplaceApi):
                         f'Error occurred when sending stocks to [{self.marketplace.id}]: {error_message} ({error_code})')
             except Exception as e:
                 logging.error(
-                   f'Exception occurred while sending stocks to marketplace ID [{self.marketplace.id}]: {str(e)}')
+                    f'Exception occurred while sending stocks to marketplace ID [{self.marketplace.id}]: {str(e)}')
 
         tasks = [send_stock_chunk(chunk) for chunk in chunks]
         await asyncio.gather(*tasks)
diff --git a/marketplaces/yandexmarket.py b/marketplaces/yandexmarket.py
index 3813616..1cb81a2 100644
--- a/marketplaces/yandexmarket.py
+++ b/marketplaces/yandexmarket.py
@@ -13,7 +13,13 @@ from utils import chunk_list
 class YandexmarketMarketplaceApi(BaseMarketplaceApi):
     def __init__(self, marketplace: Marketplace):
         self.marketplace = marketplace
-        auth_data = json.loads(marketplace.auth_data)
+        self.is_valid = True
+        try:
+            auth_data = json.loads(marketplace.auth_data)
+        except Exception:
+            logging.error(f"Couldn't load auth data for marketplace [{self.marketplace.id}]")
+            self.is_valid = False
+            return
         access_token = auth_data.get('accessToken')
 
         self.limiter_key = str(marketplace.company_id) + str(access_token) + str(self.marketplace.campaign_id)
@@ -32,6 +38,8 @@ class YandexmarketMarketplaceApi(BaseMarketplaceApi):
     async def update_stocks(self, data: Union[list, dict]):
         if type(data) is not list:
             return
+        if not self.is_valid:
+            return
         campaign_id = self.marketplace.campaign_id
         max_stocks = 2000
         chunks = chunk_list(data, max_stocks)