diff --git a/lib/import_export/category_exporter.rb b/lib/import_export/category_exporter.rb
index 61e1648cd12..4036ed783f4 100644
--- a/lib/import_export/category_exporter.rb
+++ b/lib/import_export/category_exporter.rb
@@ -35,11 +35,11 @@ module ImportExport
 
       # export groups that are mentioned in category permissions
       group_names = []
-      auto_group_names = Group::AUTO_GROUPS.keys
+      auto_group_names = Group::AUTO_GROUPS.keys.map(&:to_s)
 
       ([@export_data[:category]] + @export_data[:subcategories]).each do |c|
         c[:permissions_params].each do |group_name, _|
-          group_names << group_name unless auto_group_names.include?(group_name)
+          group_names << group_name unless auto_group_names.include?(group_name.to_s)
         end
       end
 
diff --git a/lib/import_export/category_importer.rb b/lib/import_export/category_importer.rb
index 3f5ce31f5ba..48ceb23f5d2 100644
--- a/lib/import_export/category_importer.rb
+++ b/lib/import_export/category_importer.rb
@@ -28,7 +28,7 @@ module ImportExport
         external_id = g.delete(:id)
         new_group = Group.find_by_name(g[:name]) || Group.create!(g)
         user_ids.each do |external_user_id|
-          new_group.add( User.find(@topic_importer.new_user_id(external_user_id)) )
+          new_group.add( User.find(@topic_importer.new_user_id(external_user_id)) ) rescue ActiveRecord::RecordNotUnique
         end
       end
     end