$git clean -df.

I went to my home directory.

.rbenv/versions/2.6.5/lib/ruby ​​/ gems/2.6.0/gems/activesupport- /lib/active_support/message_encryptor.rb:206: in `rescue in _decrypt': ActiveSupport :: MessageEncryptor :: InvalidMessage (ActiveSupport :: MessageEncryptor :: InvalidMessage)
.rbenv/versions/2.6.5/lib/ruby ​​/ gems/2.6.0/gems/activesupport- /lib/active_support/message_encryptor.rb:201: in `final': OpenSSL :: Cipher :: CipherError
Rails s cannot be done with the error.
The cause is that I did $git clean -df. In my home directory.
Newly created applications can rails s and existing ones will get the above error.
Thanks for your understanding.