Mongo::Error::NoServerAvailable: No server is available matching preference

gistfile1.txt

Mongo::Error::NoServerAvailable: No server is available matching preference: #<Mongo::ServerSelector::Primary:0x70190986379200 tag_sets=[] max_staleness=nil> using server_selection_timeout=30 and local_threshold=0.015
	from /Users/ipatov/.rvm/gems/ruby-2.4.1/gems/mongo-2.5.0/lib/mongo/server_selector/selectable.rb:115:in `select_server'
	from /Users/ipatov/.rvm/gems/ruby-2.4.1/gems/mongo-2.5.0/lib/mongo/collection/view/readable.rb:139:in `block in count'
	from /Users/ipatov/.rvm/gems/ruby-2.4.1/gems/mongo-2.5.0/lib/mongo/retryable.rb:44:in `read_with_retry'
	from /Users/ipatov/.rvm/gems/ruby-2.4.1/gems/mongo-2.5.0/lib/mongo/collection/view/readable.rb:138:in `count'
	from /Users/ipatov/.rvm/gems/ruby-2.4.1/gems/mongoid-6.1.1/lib/mongoid/contextual/mongo.rb:71:in `block in count'
	from /Users/ipatov/.rvm/gems/ruby-2.4.1/gems/mongoid-6.1.1/lib/mongoid/contextual/mongo.rb:522:in `try_cache'
	from /Users/ipatov/.rvm/gems/ruby-2.4.1/gems/mongoid-6.1.1/lib/mongoid/contextual/mongo.rb:71:in `count'
	from /Users/ipatov/.rvm/gems/ruby-2.4.1/gems/mongoid-6.1.1/lib/mongoid/contextual.rb:20:in `count'
	from (irb):2
	from /Users/ipatov/.rvm/gems/ruby-2.4.1/gems/railties-5.0.6/lib/rails/commands/console.rb:65:in `start'
	from /Users/ipatov/.rvm/gems/ruby-2.4.1/gems/railties-5.0.6/lib/rails/commands/console_helper.rb:9:in `start'
	from /Users/ipatov/.rvm/gems/ruby-2.4.1/gems/railties-5.0.6/lib/rails/commands/commands_tasks.rb:78:in `console'
	from /Users/ipatov/.rvm/gems/ruby-2.4.1/gems/railties-5.0.6/lib/rails/commands/commands_tasks.rb:49:in `run_command!'
	from /Users/ipatov/.rvm/gems/ruby-2.4.1/gems/railties-5.0.6/lib/rails/commands.rb:18:in `<top (required)>'
	from /Users/ipatov/.rvm/gems/ruby-2.4.1/gems/activesupport-5.0.6/lib/active_support/dependencies.rb:293:in `require'
	from /Users/ipatov/.rvm/gems/ruby-2.4.1/gems/activesupport-5.0.6/lib/active_support/dependencies.rb:293:in `block in require'
	from /Users/ipatov/.rvm/gems/ruby-2.4.1/gems/activesupport-5.0.6/lib/active_support/dependencies.rb:259:in `load_dependency'
	from /Users/ipatov/.rvm/gems/ruby-2.4.1/gems/activesupport-5.0.6/lib/active_support/dependencies.rb:293:in `require'
	from /Users/ipatov/rails_projects/apps/bitcoin/bin/rails:9:in `<top (required)>'
	from /Users/ipatov/.rvm/gems/ruby-2.4.1/gems/activesupport-5.0.6/lib/active_support/dependencies.rb:287:in `load'
	from /Users/ipatov/.rvm/gems/ruby-2.4.1/gems/activesupport-5.0.6/lib/active_support/dependencies.rb:287:in `block in load'
	from /Users/ipatov/.rvm/gems/ruby-2.4.1/gems/activesupport-5.0.6/lib/active_support/dependencies.rb:259:in `load_dependency'
	from /Users/ipatov/.rvm/gems/ruby-2.4.1/gems/activesupport-5.0.6/lib/active_support/dependencies.rb:287:in `load'
	from /Users/ipatov/.rvm/rubies/ruby-2.4.1/lib/ruby/site_ruby/2.4.0/rubygems/core_ext/kernel_require.rb:55:in `require'
	from /Users/ipatov/.rvm/rubies/ruby-2.4.1/lib/ruby/site_ruby/2.4.0/rubygems/core_ext/kernel_require.rb:55:in `require'
	from -e:1:in `<main>'