Server starts in release mode but does not start in debug mode

We are using foreman and procfile and this used to work in RubyMine 8.0. Release version starts up but the debug version displays the error --- sneakers.1         |     NoMethodError: undefined method `close' for nil:NilClass

1. The foreman debug configuration has the arguments:  start -e .env -f Procfile -p 3000   

2. The Procfile has

web:  bundle exec puma  -C config/puma.rb

sneakers: bundle exec rake sneakers:run

It is a Rails 5 project.
Any help will be appreciated.