whenever error "Bundler::GemNotFound: Your bundle is locked to aasm"

I got message in cron_log.log

Bundler::GemNotFound: Your bundle is locked to aasm (4.11.1), but that version could not be found in any of the sources listed in your Gemfile. If you haven't changed sources, that means the author of aasm (4.11.1) has removed it. You'll need to update your bundle to a different version of aasm (4.11.1) that hasn't been removed in order to install.
  /usr/local/lib/ruby/gems/2.3.0/gems/bundler-1.13.2/lib/bundler/definition.rb:179:in `rescue in specs'
  /usr/local/lib/ruby/gems/2.3.0/gems/bundler-1.13.2/lib/bundler/definition.rb:173:in `specs'
  /usr/local/lib/ruby/gems/2.3.0/gems/bundler-1.13.2/lib/bundler/definition.rb:233:in `specs_for'
  /usr/local/lib/ruby/gems/2.3.0/gems/bundler-1.13.2/lib/bundler/definition.rb:222:in `requested_specs'
  /usr/local/lib/ruby/gems/2.3.0/gems/bundler-1.13.2/lib/bundler/runtime.rb:118:in `block in definition_method'
  /usr/local/lib/ruby/gems/2.3.0/gems/bundler-1.13.2/lib/bundler/runtime.rb:19:in `setup'
  /usr/local/lib/ruby/gems/2.3.0/gems/bundler-1.13.2/lib/bundler.rb:99:in `setup'
  /usr/local/lib/ruby/gems/2.3.0/gems/bundler-1.13.2/lib/bundler/setup.rb:20:in `<top (required)>'
  /usr/local/Cellar/ruby/2.3.1_2/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
  /usr/local/Cellar/ruby/2.3.1_2/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'

my code

set :output, "./cron_log.log"

every '* * * * *' do
  runner 'User.send_maill'
end

How do I fix this ?

Start with the reported cron configuration and cron_log.log output; compare how runner 'User.send_maill' runs under cron with the Bundler environment shown in the stack trace. Done would require a reproducible diagnosis and a project-level correction, but the issue names no project file or test to change.