diff --git a/tiramisu/setting.py b/tiramisu/setting.py
index 6e674ea..6e8a438 100644
--- a/tiramisu/setting.py
+++ b/tiramisu/setting.py
@@ -579,12 +579,14 @@ class Settings(object):
                                 prop_msg = _('property')
                             else:
                                 prop_msg = _('properties')
-                            raise RequirementError(_('cannot access to option "{0}" because '
+                            err = RequirementError(_('cannot access to option "{0}" because '
                                                      'required option "{1}" has {2} {3}'
                                                      '').format(option_bag.option.impl_get_display_name(),
                                                                 option.impl_get_display_name(),
                                                                 prop_msg,
                                                                 display_list(list(properties), add_quote=True)))
+                            err.proptype = properties
+                            raise err
                         # transitive action, add action
                         if operator != 'and':
                             if readable:
@@ -778,12 +780,11 @@ class Settings(object):
         if 'mandatory' in option_bag.config_bag.properties:
             values = option_bag.config_bag.context.cfgimpl_get_values()
             is_mandatory = False
-            if ('permissive' in option_bag.config_bag.properties) and \
-                    'mandatory' in option_bag.config_bag.permissives:
-                pass
-            elif 'mandatory' in option_bag.properties and values.isempty(option_bag.option,
-                                                                         value,
-                                                                         index=option_bag.index):
+            if not ('permissive' in option_bag.config_bag.properties and
+                    'mandatory' in option_bag.config_bag.permissives) and \
+                    'mandatory' in option_bag.properties and values.isempty(option_bag.option,
+                                                                                 value,
+                                                                                 index=option_bag.index):
                 is_mandatory = True
             if 'empty' in option_bag.properties and values.isempty(option_bag.option,
                                                                    value,
diff --git a/tiramisu/todict.py b/tiramisu/todict.py
index 2c2c7e0..2a92619 100644
--- a/tiramisu/todict.py
+++ b/tiramisu/todict.py
@@ -319,8 +319,6 @@ class TiramisuDict:
                  root=None,
                  clearable="all",
                  remotable="minimum"):
-        if 'demoting_error_warning' not in config.property.get():
-            raise ValueError('demoting_error_warning property is mandatory')
         self.config = config
         self.root = root
         self.requires = None
@@ -390,7 +388,7 @@ class TiramisuDict:
                                    schema,
                                    'force_store_value' in props_no_requires)
             childapi_option = childapi.option
-            if model is not None:
+            if model is not None and childapi.option.isoptiondescription() or not childapi_option.issymlinkoption():
                 self.gen_model(model,
                                childapi,
                                path,
diff --git a/tiramisu/value.py b/tiramisu/value.py
index 08f974d..04e369c 100644
--- a/tiramisu/value.py
+++ b/tiramisu/value.py
@@ -17,7 +17,7 @@
 # ____________________________________________________________
 import weakref
 from typing import Optional, Any, Callable
-from .error import ConfigError, PropertiesOptionError
+from .error import ConfigError, PropertiesOptionError, RequirementError
 from .setting import owners, undefined, forbidden_owners, OptionBag, ConfigBag
 from .autolib import carry_out_calculation
 from .function import Params
@@ -251,7 +251,7 @@ class Values(object):
             isempty = value is None or (not allow_empty_list and value == []) or \
                 None in value or empty in value
         else:
-            isempty = value is None or value == empty
+            isempty = value is None or value == empty or (opt.impl_is_submulti() and value == [])
         return isempty
 
     #______________________________________________________________________
@@ -602,6 +602,8 @@ class Values(object):
                 except PropertiesOptionError as err:
                     if err.proptype == ['mandatory']:
                         yield path
+                except RequirementError:
+                    pass
                 except ConfigError as err:
                     #assume that uncalculated value is an empty value
                     yield path