diff --git a/middleware/app_be/services/mongodbservice.py b/middleware/app_be/services/mongodbservice.py
index 5bbdce2..cffef2c 100644
--- a/middleware/app_be/services/mongodbservice.py
+++ b/middleware/app_be/services/mongodbservice.py
@@ -60,6 +60,8 @@ class MongoDBService:
             metadata['identifier'] = identifier
             metadata['location'] = [metadata['longitude'], metadata['latitude']]
             metadata['sha512'] = create_sha512(decoded_image)
+            metadata['version'] = 0
+            metadata['previous'] = ''
             col.insert_one(metadata)
 
         except:
@@ -79,10 +81,10 @@ class MongoDBService:
 
         metadata_orig = MongoDBService.getSingle(identifier)
         metadata_new = metadata_orig
-        metadata_new['previous'] = identifier + '_' + metadata_orig['version']
+        metadata_new['previous'] = identifier + '_' + str(metadata_orig['version'])
         metadata_new['version'] = str(int(metadata_new['version']) + 1)  # Increment version by one
 
-        identifier_changed = identifier + '_' + metadata_orig['version']  # Set identifier to include version
+        identifier_changed = identifier + '_' + str(metadata_orig['version'])  # Set identifier to include version
         col.update_one(old, {"$set": {"identifier": identifier_changed, "filename": identifier_changed + '.jpg'}})
 
         print("MongoDBService: Old object is ", col.find_one({"identifier": identifier_changed}))