tcp_server.rb:18:in `unpack_sockaddr_in': no implicit conversion of nil into String (TypeError)

Question

I am setting up Redmine 4.0.3 on Windows system, ruby 2.5.1, thin server. The installation succeeded but when I tried to start Redmine an error occurred and thin server did not start. Here is the trace log of whaat happened:

Thin web server (v1.7.2 codename Bachmanity)
Maximum connections set to 1024
Listening on 0.0.0.0:3000, CTRL+C to stop
Traceback (most recent call last):
        20: from C:/Ruby25/bin/thin:23:in `<main>'
        19: from C:/Ruby25/bin/thin:23:in `load'
        18: from C:/Ruby25/lib/ruby/gems/2.5.0/gems/thin-1.7.2/bin/thin:6:in `<top (required)>'
        17: from C:/Ruby25/lib/ruby/gems/2.5.0/gems/thin-1.7.2/lib/thin/runner.rb:159:in `run!'
        16: from C:/Ruby25/lib/ruby/gems/2.5.0/gems/thin-1.7.2/lib/thin/runner.rb:203:in `run_command'
        15: from C:/Ruby25/lib/ruby/gems/2.5.0/gems/thin-1.7.2/lib/thin/controllers/controller.rb:87:in `start'
        14: from C:/Ruby25/lib/ruby/gems/2.5.0/gems/thin-1.7.2/lib/thin/server.rb:162:in `start'
        13: from C:/Ruby25/lib/ruby/gems/2.5.0/gems/thin-1.7.2/lib/thin/backends/base.rb:73:in `start'
        12: from C:/Ruby25/lib/ruby/gems/2.5.0/gems/eventmachine-1.2.7-x86-mingw32/lib/eventmachine.rb:196:in `run'
        11: from C:/Ruby25/lib/ruby/gems/2.5.0/gems/eventmachine-1.2.7-x86-mingw32/lib/em/pure_ruby.rb:144:in `run_machine'
        10: from C:/Ruby25/lib/ruby/gems/2.5.0/gems/eventmachine-1.2.7-x86-mingw32/lib/em/pure_ruby.rb:547:in `run'
         9: from C:/Ruby25/lib/ruby/gems/2.5.0/gems/eventmachine-1.2.7-x86-mingw32/lib/em/pure_ruby.rb:547:in `loop'
         8: from C:/Ruby25/lib/ruby/gems/2.5.0/gems/eventmachine-1.2.7-x86-mingw32/lib/em/pure_ruby.rb:551:in `block in run'
         7: from C:/Ruby25/lib/ruby/gems/2.5.0/gems/eventmachine-1.2.7-x86-mingw32/lib/em/pure_ruby.rb:568:in `run_timers'
         6: from C:/Ruby25/lib/ruby/2.5.0/set.rb:774:in `each'
         5: from C:/Ruby25/lib/ruby/2.5.0/set.rb:774:in `each'
         4: from C:/Ruby25/lib/ruby/gems/2.5.0/gems/eventmachine-1.2.7-x86-mingw32/lib/em/pure_ruby.rb:571:in `block in run_timers'
         3: from C:/Ruby25/lib/ruby/gems/2.5.0/gems/eventmachine-1.2.7-x86-mingw32/lib/eventmachine.rb:1546:in `event_callback'
         2: from C:/Ruby25/lib/ruby/gems/2.5.0/gems/thin-1.7.2/lib/thin/backends/base.rb:63:in `block in start'
         1: from C:/Ruby25/lib/ruby/gems/2.5.0/gems/thin-1.7.2/lib/thin/backends/tcp_server.rb:18:in `connect'
C:/Ruby25/lib/ruby/gems/2.5.0/gems/thin-1.7.2/lib/thin/backends/tcp_server.rb:18:in `unpack_sockaddr_in': no implicit conversion of nil into String (TypeError)

I do not what is the cause of that error. What I have to change so as to make thin server start?

Answer 1

delete all versions of eventmachine,then:

gem install eventmachine