diff --git a/taiga/projects/services/members.py b/taiga/projects/services/members.py
index 4de432ab..8c9bf265 100644
--- a/taiga/projects/services/members.py
+++ b/taiga/projects/services/members.py
@@ -88,6 +88,9 @@ def get_max_memberships_for_project(project):
 
     :return: a number or null.
     """
+    if project.owner is None:
+        return None
+
     if project.is_private:
         return project.owner.max_memberships_private_projects
     return project.owner.max_memberships_public_projects
@@ -111,6 +114,9 @@ def check_if_project_can_have_more_memberships(project, total_new_memberships):
 
     :return: {bool, error_mesage} return a tuple (can add new members?, error message).
     """
+    if project.owner is None:
+        return False, _("Project without owner")
+        
     if project.is_private:
         total_memberships = project.memberships.count() + total_new_memberships
         max_memberships = project.owner.max_memberships_private_projects
diff --git a/taiga/projects/services/projects.py b/taiga/projects/services/projects.py
index 49abc2e5..f56a9941 100644
--- a/taiga/projects/services/projects.py
+++ b/taiga/projects/services/projects.py
@@ -25,6 +25,7 @@ ERROR_MAX_PUBLIC_PROJECTS_MEMBERSHIPS = 'max_public_projects_memberships'
 ERROR_MAX_PRIVATE_PROJECTS_MEMBERSHIPS = 'max_private_projects_memberships'
 ERROR_MAX_PUBLIC_PROJECTS = 'max_public_projects'
 ERROR_MAX_PRIVATE_PROJECTS = 'max_private_projects'
+ERROR_PROJECT_WITHOUT_OWNER = 'project_without_owner'
 
 def check_if_project_privacity_can_be_changed(project):
     """Return if the project privacity can be changed from private to public or viceversa.
@@ -33,6 +34,9 @@ def check_if_project_privacity_can_be_changed(project):
 
     :return: A dict like this {'can_be_updated': bool, 'reason': error message}.
     """
+    if project.owner is None:
+        return {'can_be_updated': False, 'reason': ERROR_PROJECT_WITHOUT_OWNER}
+
     if project.is_private:
         current_memberships = project.memberships.count()
         max_memberships = project.owner.max_memberships_public_projects
@@ -66,6 +70,9 @@ def check_if_project_can_be_created_or_updated(project):
 
     :return: {bool, error_mesage} return a tuple (can be created or updated, error message).
     """
+    if project.owner is None:
+        return {'can_be_updated': False, 'reason': ERROR_PROJECT_WITHOUT_OWNER}
+
     if project.is_private:
         current_projects = project.owner.owned_projects.filter(is_private=True).count()
         max_projects = project.owner.max_private_projects
@@ -100,6 +107,9 @@ def check_if_project_can_be_transfered(project, new_owner):
 
     :return: {bool, error_mesage} return a tuple (can be transfered?, error message).
     """
+    if project.owner is None:
+        return {'can_be_updated': False, 'reason': ERROR_PROJECT_WITHOUT_OWNER}
+
     if project.owner == new_owner:
         return (True, None)
 
@@ -136,6 +146,9 @@ def check_if_project_is_out_of_owner_limits(project):
 
     :return: bool
     """
+    if project.owner is None:
+        return {'can_be_updated': False, 'reason': ERROR_PROJECT_WITHOUT_OWNER}
+
     if project.is_private:
         current_memberships = project.memberships.count()
         max_memberships = project.owner.max_memberships_private_projects
diff --git a/taiga/users/admin.py b/taiga/users/admin.py
index 1d03d0cf..9c52a9bb 100644
--- a/taiga/users/admin.py
+++ b/taiga/users/admin.py
@@ -64,7 +64,6 @@ class MembershipsInline(admin.TabularInline):
 
     def project_owner(self, obj):
         if obj.project and obj.project.owner:
-            #return obj.project.owner.get_full_name()
             return "{} (@{})".format(obj.project.owner.get_full_name(), obj.project.owner.username)
         return None
     project_owner.short_description = _("owner")