After upgrading CloudForms Management Engine from 5.7 to 5.8, the error "uninitialized constant MiqEnvironment::Process (NameError)" prevents the appliance from starting

Issue

• After upgrading CloudForms Management Engine from 5.7 to 5.8, the error "uninitialized constant MiqEnvironment::Process (NameError)" stops the appliance from coming online.
• Any attempts to load rails console or start the appliance with systemctl start evmserverd or bundle exec rake evm:start see a similar backtrace to the following:

# vmdb
# bundle exec rails console
/var/www/miq/vmdb/config/initializers/orig-session_store.rb:3:in `<top (required)>': uninitialized constant MiqEnvironment::Process (NameError)
        from /opt/rh/cfme-gemset/gems/railties-5.0.3/lib/rails/engine.rb:648:in `block in load_config_initializer'
        from /opt/rh/cfme-gemset/gems/activesupport-5.0.3/lib/active_support/notifications.rb:166:in `instrument'
        from /opt/rh/cfme-gemset/gems/railties-5.0.3/lib/rails/engine.rb:647:in `load_config_initializer'
        from /opt/rh/cfme-gemset/gems/railties-5.0.3/lib/rails/engine.rb:612:in `block (2 levels) in <class:Engine>'
        from /opt/rh/cfme-gemset/gems/railties-5.0.3/lib/rails/engine.rb:611:in `each'
        from /opt/rh/cfme-gemset/gems/railties-5.0.3/lib/rails/engine.rb:611:in `block in <class:Engine>'
        from /opt/rh/cfme-gemset/gems/railties-5.0.3/lib/rails/initializable.rb:30:in `instance_exec'
        from /opt/rh/cfme-gemset/gems/railties-5.0.3/lib/rails/initializable.rb:30:in `run'
        from /opt/rh/cfme-gemset/gems/railties-5.0.3/lib/rails/initializable.rb:55:in `block in run_initializers'
        from /opt/rh/rh-ruby23/root/usr/share/ruby/tsort.rb:228:in `block in tsort_each'
        from /opt/rh/rh-ruby23/root/usr/share/ruby/tsort.rb:350:in `block (2 levels) in each_strongly_connected_component'
        from /opt/rh/rh-ruby23/root/usr/share/ruby/tsort.rb:422:in `block (2 levels) in each_strongly_connected_component_from'
        from /opt/rh/rh-ruby23/root/usr/share/ruby/tsort.rb:431:in `each_strongly_connected_component_from'
        from /opt/rh/rh-ruby23/root/usr/share/ruby/tsort.rb:421:in `block in each_strongly_connected_component_from'
        from /opt/rh/cfme-gemset/gems/railties-5.0.3/lib/rails/initializable.rb:44:in `each'
        from /opt/rh/cfme-gemset/gems/railties-5.0.3/lib/rails/initializable.rb:44:in `tsort_each_child'
        from /opt/rh/rh-ruby23/root/usr/share/ruby/tsort.rb:415:in `call'
        from /opt/rh/rh-ruby23/root/usr/share/ruby/tsort.rb:415:in `each_strongly_connected_component_from'
        from /opt/rh/rh-ruby23/root/usr/share/ruby/tsort.rb:349:in `block in each_strongly_connected_component'
        from /opt/rh/rh-ruby23/root/usr/share/ruby/tsort.rb:347:in `each'
        from /opt/rh/rh-ruby23/root/usr/share/ruby/tsort.rb:347:in `call'
        from /opt/rh/rh-ruby23/root/usr/share/ruby/tsort.rb:347:in `each_strongly_connected_component'
        from /opt/rh/rh-ruby23/root/usr/share/ruby/tsort.rb:226:in `tsort_each'
        from /opt/rh/rh-ruby23/root/usr/share/ruby/tsort.rb:205:in `tsort_each'
        from /opt/rh/cfme-gemset/gems/railties-5.0.3/lib/rails/initializable.rb:54:in `run_initializers'
        from /opt/rh/cfme-gemset/gems/railties-5.0.3/lib/rails/application.rb:352:in `initialize!'
        from /opt/rh/cfme-gemset/gems/railties-5.0.3/lib/rails/railtie.rb:193:in `public_send'
        from /opt/rh/cfme-gemset/gems/railties-5.0.3/lib/rails/railtie.rb:193:in `method_missing'
        from /var/www/miq/vmdb/config/environment.rb:5:in `<top (required)>'
        from /opt/rh/cfme-gemset/gems/railties-5.0.3/lib/rails/application.rb:328:in `require_environment!'
        from /opt/rh/cfme-gemset/gems/railties-5.0.3/lib/rails/commands/commands_tasks.rb:157:in `require_application_and_environment!'
        from /opt/rh/cfme-gemset/gems/railties-5.0.3/lib/rails/commands/commands_tasks.rb:77:in `console'
        from /opt/rh/cfme-gemset/gems/railties-5.0.3/lib/rails/commands/commands_tasks.rb:49:in `run_command!'
        from /opt/rh/cfme-gemset/gems/railties-5.0.3/lib/rails/commands.rb:18:in `<top (required)>'
        from bin/rails:4:in `require'
        from bin/rails:4:in `<main>'