Redmine lock inactive users

Question

I'm trying to create a rake file which will be linked to crontab, and will have the ability to lock users which are inactive for 90 days in the group ID 600, but something is not correct in the file. this is the lock_inactive_users.rake

namespace :redmine do
  desc "Lock inactive users" 
  task lock_inactive_users: :environment do
    inactive_users = User.joins(:groups)
                         .where('groups.id = ?', 600)
                         .where(type: 'User')
                         .where('last_login_on < ?', 90.days.ago)

    inactive_users.find_each(batch_size: 500) do |user|
      user.update(status: User::STATUS_LOCKED)
      puts "User #{user.login} (ID: #{user.id}) has been locked." 
    end
  end
end

while executing the file Im ending with error bundle exec rake redmine:lock_inactive_users RAILS_ENV=production

ActiveRecord::StatementInvalid: PG::UndefinedTable: ERROR:  missing FROM-clause entry for table "groups"

Any guidance will be much appreciated