diff --git a/apps/assets/tasks.py b/apps/assets/tasks.py
index dd660bc42..f1773df11 100644
--- a/apps/assets/tasks.py
+++ b/apps/assets/tasks.py
@@ -22,7 +22,7 @@ TIMEOUT = 60
 logger = get_logger(__file__)
 CACHE_MAX_TIME = 60*60*60
 disk_pattern = re.compile(r'^hd|sd|xvd|vd')
-PERIOD_TASK = os.environ.get("PERIOD_TASK", "on")
+PERIOD_TASK = os.environ.get("PERIOD_TASK", "off")
 
 
 @shared_task
diff --git a/apps/common/validators.py b/apps/common/validators.py
index 9a4c1e501..b273bd1de 100644
--- a/apps/common/validators.py
+++ b/apps/common/validators.py
@@ -4,4 +4,4 @@ from django.core.validators import RegexValidator
 from django.utils.translation import ugettext_lazy as _
 
 
-alphanumeric = RegexValidator(r'^[0-9a-zA-Z_-]*$', _('Special char not allowed'))
\ No newline at end of file
+alphanumeric = RegexValidator(r'^[0-9a-zA-Z_@\-\.]*$', _('Special char not allowed'))
\ No newline at end of file
diff --git a/apps/perms/serializers.py b/apps/perms/serializers.py
index baa823a6f..0f0419eff 100644
--- a/apps/perms/serializers.py
+++ b/apps/perms/serializers.py
@@ -9,7 +9,7 @@ from common.fields import StringManyToManyField
 class AssetPermissionCreateUpdateSerializer(serializers.ModelSerializer):
     class Meta:
         model = AssetPermission
-        exclude = ('id', 'created_by', 'date_created')
+        exclude = ('created_by', 'date_created')
 
 
 class AssetPermissionListSerializer(serializers.ModelSerializer):