railsサーバーが立てることができません。

Question

プログラミングの学習の途中で自分で環境構築をしていく途中なんですが、ここ2日ほど躓いています。
サイトで調べて、rails　newで新しくappの作成はできました。
しかし、TestAppのディレクトリに移り、rails s実行しても以下のような表記になってしまいます。localhost:3000につながらず、原因がわからず困ってます。Rubyに詳しい方、解決方法を教えて頂けますでしょうか?

=> Booting Puma
=> Rails 6.0.2.2 application starting in development
=> Run rails server --help for more startup options
Exiting
Traceback (most recent call last):
48: from bin/rails:4:in <main>' 47: from bin/rails:4:in require'
46: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/railties-6.0.2.2/lib/rails/commands.rb:18:in <top (required)>' 45: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/railties-6.0.2.2/lib/rails/command.rb:46:in invoke'
44: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/railties-6.0.2.2/lib/rails/command/base.rb:69:in perform' 43: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/thor-1.0.1/lib/thor.rb:392:in dispatch'
42: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/thor-1.0.1/lib/thor/invocation.rb:127:in invoke_command' 41: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/thor-1.0.1/lib/thor/command.rb:27:in run'
40: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/railties-6.0.2.2/lib/rails/commands/server/server_command.rb:138:in perform' 39: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/railties-6.0.2.2/lib/rails/commands/server/server_command.rb:138:in tap'
38: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/railties-6.0.2.2/lib/rails/commands/server/server_command.rb:147:in block in perform' 37: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/railties-6.0.2.2/lib/rails/commands/server/server_command.rb:37:in start'
36: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/railties-6.0.2.2/lib/rails/commands/server/server_command.rb:77:in log_to_stdout' 35: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/rack-2.2.2/lib/rack/server.rb:422:in wrapped_app'
34: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/rack-2.2.2/lib/rack/server.rb:249:in app' 33: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/rack-2.2.2/lib/rack/server.rb:349:in build_app_and_options_from_config'
32: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/rack-2.2.2/lib/rack/builder.rb:66:in parse_file' 31: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/rack-2.2.2/lib/rack/builder.rb:105:in load_file'
30: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/rack-2.2.2/lib/rack/builder.rb:116:in new_from_string' 29: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/rack-2.2.2/lib/rack/builder.rb:116:in eval'
28: from config.ru:3:in block in <main>' 27: from config.ru:3:in require_relative'
26: from C:/Users/takay/Testapp/config/environment.rb:5:in <top (required)>' 25: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/railties-6.0.2.2/lib/rails/application.rb:363:in initialize!'
24: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/railties-6.0.2.2/lib/rails/initializable.rb:60:in run_initializers' 23: from C:/Ruby25-x64/lib/ruby/2.5.0/tsort.rb:205:in tsort_each'
22: from C:/Ruby25-x64/lib/ruby/2.5.0/tsort.rb:226:in tsort_each' 21: from C:/Ruby25-x64/lib/ruby/2.5.0/tsort.rb:347:in each_strongly_connected_component'
20: from C:/Ruby25-x64/lib/ruby/2.5.0/tsort.rb:347:in call' 19: from C:/Ruby25-x64/lib/ruby/2.5.0/tsort.rb:347:in each'
18: from C:/Ruby25-x64/lib/ruby/2.5.0/tsort.rb:349:in block in each_strongly_connected_component' 17: from C:/Ruby25-x64/lib/ruby/2.5.0/tsort.rb:431:in each_strongly_connected_component_from'
16: from C:/Ruby25-x64/lib/ruby/2.5.0/tsort.rb:350:in block (2 levels) in each_strongly_connected_component' 15: from C:/Ruby25-x64/lib/ruby/2.5.0/tsort.rb:228:in block in tsort_each'
14: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/railties-6.0.2.2/lib/rails/initializable.rb:61:in block in run_initializers' 13: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/railties-6.0.2.2/lib/rails/initializable.rb:32:in run'
12: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/railties-6.0.2.2/lib/rails/initializable.rb:32:in instance_exec' 11: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/webpacker-4.2.2/lib/webpacker/railtie.rb:84:in block in class:Engine'
10: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/webpacker-4.2.2/lib/webpacker.rb:35:in bootstrap' 9: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/webpacker-4.2.2/lib/webpacker/commands.rb:25:in bootstrap'
8: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/webpacker-4.2.2/lib/webpacker/manifest.rb:18:in refresh' 7: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/webpacker-4.2.2/lib/webpacker/manifest.rb:83:in load'
6: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/webpacker-4.2.2/lib/webpacker/configuration.rb:51:in public_manifest_path' 5: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/webpacker-4.2.2/lib/webpacker/configuration.rb:47:in public_output_path'
4: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/webpacker-4.2.2/lib/webpacker/configuration.rb:43:in public_path' 3: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/webpacker-4.2.2/lib/webpacker/configuration.rb:84:in fetch'
2: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/webpacker-4.2.2/lib/webpacker/configuration.rb:88:in data' 1: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/webpacker-4.2.2/lib/webpacker/configuration.rb:91:in load'
C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/webpacker-4.2.2/lib/webpacker/configuration.rb:95:in `rescue in load': Webpacker configuration file not found C:/Users/takay/Testapp/config/webpacker.yml. Please run rails webpacker:install Error: No such file or directory @ rb_sysopen - C:/Users/takay/Testapp/config/webpacker.yml (RuntimeError)

補足
windows10
rails -v
Rails 6.0.2.2
ruby -v
ruby 2.5.7p206 (2019-10-01 revision 67816) [x64-mingw32]

*** LOCAL GEMS ***

actioncable (6.0.2.2)
actionmailbox (6.0.2.2)
actionmailer (6.0.2.2)
actionpack (6.0.2.2)
actiontext (6.0.2.2)
actionview (6.0.2.2)
activejob (6.0.2.2)
activemodel (6.0.2.2)
activerecord (6.0.2.2)
activestorage (6.0.2.2)
activesupport (6.0.2.2)
addressable (2.7.0)
bigdecimal (default: 1.3.4)
bindex (0.8.1)
bootsnap (1.4.6)
builder (3.2.4)
bundler (2.1.4)
byebug (11.1.1)
capybara (3.31.0)
childprocess (3.0.0)
cmath (default: 1.0.0)
concurrent-ruby (1.1.6)
crass (1.0.6)
csv (default: 1.0.0)
date (default: 1.0.0)
dbm (default: 1.0.0)
did_you_mean (1.2.0)
erubi (1.9.0)
etc (default: 1.0.0)
fcntl (default: 1.0.0)
ffi (1.12.2 x64-mingw32)
fiddle (default: 1.0.0)
fileutils (default: 1.0.2)
gdbm (default: 2.0.0)
globalid (0.4.2)
i18n (1.8.2)
io-console (default: 0.4.6)
ipaddr (default: 1.2.0)
jbuilder (2.10.0)
json (default: 2.1.0)
loofah (2.4.0)
mail (2.7.1)
marcel (0.3.3)
method_source (1.0.0)
mimemagic (0.3.4)
mini_mime (1.0.2)
mini_portile2 (2.4.0)
minitest (5.14.0, 5.10.3)
msgpack (1.3.3 x64-mingw32)
mysql2 (0.5.3 x64-mingw32)
net-telnet (0.1.1)
nio4r (2.5.2)
nokogiri (1.10.9 x64-mingw32)
openssl (default: 2.1.2)
power_assert (1.1.1)
psych (default: 3.0.2)
public_suffix (4.0.3)
puma (4.3.3)
rack (2.2.2)
rack-proxy (0.6.5)
rack-test (1.1.0)
rails (6.0.2.2)
rails-dom-testing (2.0.3)
rails-html-sanitizer (1.3.0)
railties (6.0.2.2)
rake (13.0.1, 12.3.0)
rdoc (default: 6.0.1.1)
regexp_parser (1.7.0)
rubygems-update (3.1.2)
rubyzip (2.3.0)
sass-rails (6.0.0)
sassc (2.2.1 x64-mingw32)
sassc-rails (2.1.2)
scanf (default: 1.0.0)
sdbm (default: 1.0.0)
selenium-webdriver (3.142.7)
sprockets (4.0.0)
sprockets-rails (3.2.1)
sqlite3 (1.4.2)
stringio (default: 0.0.1)
strscan (default: 1.0.0)
test-unit (3.2.7)
thor (1.0.1)
thread_safe (0.3.6)
tilt (2.0.10)
turbolinks (5.2.1)
turbolinks-source (5.2.0)
tzinfo (1.2.6)
tzinfo-data (1.2019.3)
web-console (4.0.1)
webdrivers (4.2.0)
webpacker (4.2.2)
webrick (default: 1.4.2)
websocket-driver (0.7.1)
websocket-extensions (0.1.4)
xmlrpc (0.3.0)
xpath (3.2.0)
zeitwerk (2.3.0)
zlib (default: 1.0.0)

Answer 1

エラーメッセージは、
" Webpacker configuration file not found C:/Users/takay/Testapp/config/webpacker.yml. "
[直訳]Webpackerの設定ファイル C:/Users/takay/Testapp/config/webpacker.yml が見つかりません。
というものですから、webpackerのインストールで問題が生じたのだと思います。

【Rails入門】Webpackerではじめるフロントエンド開発！Rails5.1対応　などの記事を参考にして、Webpackerを再インストールしてみては如何でしょう。

Comments

[takayuki4849]

ありがとうございます！試してみます。