diff --git a/app/models/environment.rb b/app/models/environment.rb
index 6b97906..f551aa3 100644
--- a/app/models/environment.rb
+++ b/app/models/environment.rb
@@ -86,7 +86,9 @@ class Environment < ActiveRecord::Base
   end
 
   def admins
-    Person.members_of(self).all(:conditions => ['role_assignments.role_id = ?', Environment::Roles.admin(self).id])
+    admin_role = Environment::Roles.admin(self)
+    return [] if admin_role.blank?
+    Person.members_of(self).all(:conditions => ['role_assignments.role_id = ?', admin_role.id])
   end
 
   # returns the available features for a Environment, in the form of a
diff --git a/app/models/person.rb b/app/models/person.rb
index 557ac24..2aac2cc 100644
--- a/app/models/person.rb
+++ b/app/models/person.rb
@@ -33,16 +33,17 @@ class Person < Profile
     { :select => 'DISTINCT profiles.*', :conditions => ['"profiles"."id" NOT IN (SELECT DISTINCT profiles.id FROM "profiles" INNER JOIN "friendships" ON "friendships"."person_id" = "profiles"."id" WHERE "friendships"."friend_id" IN (%s))' % resources.map(&:id)] }
   }
 
-  def has_permission_with_admin?(permission, profile)
-    return true if profile.admins.include?(self) || profile.environment.admins.include?(self)
-    has_permission_without_admin?(permission, profile)
+  def has_permission_with_admin?(permission, resource)
+    return true if resource.blank? || resource.admins.include?(self)
+    return true if resource.kind_of?(Profile) && resource.environment.admins.include?(self)
+    has_permission_without_admin?(permission, resource)
   end
   alias_method_chain :has_permission?, :admin
 
-  def has_permission_with_plugins?(permission, profile)
-    permissions = [has_permission_without_plugins?(permission, profile)]
+  def has_permission_with_plugins?(permission, resource)
+    permissions = [has_permission_without_plugins?(permission, resource)]
     permissions += plugins.map do |plugin|
-      plugin.has_permission?(self, permission, profile)
+      plugin.has_permission?(self, permission, resource)
     end
     permissions.include?(true)
   end
diff --git a/app/models/profile.rb b/app/models/profile.rb
index c7cdfea..a592c58 100644
--- a/app/models/profile.rb
+++ b/app/models/profile.rb
@@ -795,7 +795,10 @@ private :generate_url, :url_options
   end
 
   def admins
-    self.members_by_role(Profile::Roles.admin(environment.id))
+    return [] if environment.blank?
+    admin_role = Profile::Roles.admin(environment.id)
+    return [] if admin_role.blank?
+    self.members_by_role(admin_role)
   end
 
   def enable_contact?
@@ -803,7 +806,7 @@ private :generate_url, :url_options
   end
 
   include Noosfero::Plugin::HotSpot
-  
+
   def folder_types
     types = Article.folder_types
     plugins.dispatch(:content_types).each {|type|
--
libgit2 0.21.2