diff --git a/api/handlers/collectionshandler.py b/api/handlers/collectionshandler.py
index ff8861fae..6f8e55180 100644
--- a/api/handlers/collectionshandler.py
+++ b/api/handlers/collectionshandler.py
@@ -4,6 +4,7 @@
 from .. import config
 from ..auth import containerauth, always_ok
 from ..dao import containerstorage
+from ..dao import APIStorageException
 
 from containerhandler import ContainerHandler
 
diff --git a/api/handlers/containerhandler.py b/api/handlers/containerhandler.py
index 66138571b..77b1bd5a9 100644
--- a/api/handlers/containerhandler.py
+++ b/api/handlers/containerhandler.py
@@ -258,9 +258,10 @@ def put(self, cont_name, **kwargs):
         if target_parent_container:
             if cont_name == 'sessions':
                 payload['group'] = target_parent_container['group']
-            payload['permissions'] = target_parent_container.get('roles')
-            if payload['permissions'] is None:
-                payload['permissions'] = target_parent_container['permissions']
+            if cont_name == 'projects':
+                payload['permissions'] = target_parent_container.get('roles', [])
+            else:
+                payload['permissions'] = target_parent_container.get('permissions', [])
 
         payload['modified'] = datetime.datetime.utcnow()
         if payload.get('timestamp'):
diff --git a/api/handlers/grouphandler.py b/api/handlers/grouphandler.py
index 6c99477b2..390ddf50c 100644
--- a/api/handlers/grouphandler.py
+++ b/api/handlers/grouphandler.py
@@ -73,6 +73,7 @@ def post(self):
         payload_validator = validators.payload_from_schema_file(self, 'group.json')
         payload_validator(payload, 'POST')
         payload['created'] = payload['modified'] = datetime.datetime.utcnow()
+        payload['roles'] = [{'_id': self.uid, 'access': 'admin', 'site': self.user_site}]
         result = mongo_validator(permchecker(self.storage.exec_op))('POST', payload=payload)
         if result.acknowledged:
             return {'_id': result.inserted_id}
diff --git a/api/handlers/listhandler.py b/api/handlers/listhandler.py
index aa1f3a06c..b350a8939 100644
--- a/api/handlers/listhandler.py
+++ b/api/handlers/listhandler.py
@@ -181,7 +181,7 @@ def _initialize_request(self, cont_name, list_name, _id, query_params=None):
         else:
             self.abort(404, 'Element {} not found in container {}'.format(_id, storage.cont_name))
         mongo_validator = validators.mongo_from_schema_file(self, config.get('storage_schema_file'))
-        input_validator = validators.payload_from_schema_file(self, config.get('payload_schema_file'))
+        input_validator = validators.payload_from_schema_file(self, config.get('input_schema_file'))
         keycheck = validators.key_check(self, config.get('storage_schema_file'))
         return container, permchecker, storage, mongo_validator, input_validator, keycheck
 
diff --git a/api/schemas/input/acquisition.json b/api/schemas/input/acquisition.json
index 7255c2b61..b7ea7a0ce 100644
--- a/api/schemas/input/acquisition.json
+++ b/api/schemas/input/acquisition.json
@@ -15,5 +15,6 @@
         "timestamp":    {"type": "string"},
         "timezone":     {"type": "string"}
     },
+    "required": ["label"],
     "additionalProperties": false
 }
diff --git a/api/schemas/input/collection.json b/api/schemas/input/collection.json
index 26c213f06..d7ff44efa 100644
--- a/api/schemas/input/collection.json
+++ b/api/schemas/input/collection.json
@@ -10,5 +10,6 @@
 
         "curator": {"type": "string"}
     },
+    "required": ["label"],
     "additionalProperties": false
 }
diff --git a/api/schemas/input/container.json b/api/schemas/input/container.json
index 41adc1ebf..9428bf0fc 100644
--- a/api/schemas/input/container.json
+++ b/api/schemas/input/container.json
@@ -4,7 +4,7 @@
     "properties": {
         "_id":          {"type": "string"},
         "public":       {"type": "boolean"},
-        "label":        {"type": "string"},
+        "label":        {"type": "string", "minLength": 1, "maxLength": 256},
         "metadata":     {"type": "object"}
     }
 }
diff --git a/api/schemas/input/file.json b/api/schemas/input/file.json
index 9e3313f42..3e8910f2f 100644
--- a/api/schemas/input/file.json
+++ b/api/schemas/input/file.json
@@ -3,8 +3,6 @@
   "type": "object",
   "properties": {
     "name":           { "type": "string" },
-    "created":        {"type": "string", "format": "date-time"},
-    "modified":       {"type": "string", "format": "date-time"},
     "type":           { "type": "string" },
     "size":           { "type": "integer" },
     "hash":           { "type": "string" },
diff --git a/api/schemas/input/project.json b/api/schemas/input/project.json
index 9b7425207..cb3dbdff7 100644
--- a/api/schemas/input/project.json
+++ b/api/schemas/input/project.json
@@ -10,5 +10,6 @@
 
         "group": {"type": "string"}
     },
+    "required": ["label"],
     "additionalProperties": false
 }
diff --git a/api/schemas/input/session.json b/api/schemas/input/session.json
index 02a55258c..92a1d5027 100644
--- a/api/schemas/input/session.json
+++ b/api/schemas/input/session.json
@@ -14,5 +14,6 @@
         "timezone":     {"type": "string"},
         "subject":      {"$ref": "subject.json"}
     },
+    "required": ["label"],
     "additionalProperties": false
 }