在总共14个宝石中找不到'railties'（> = 0.a）（Gem :: LoadError）

Question

运行时：$ rails新应用程序出现错误！ （最近更新的红宝石。）

macOS Mojave 10.14.6

rails -v = ruby 2.6.3p62 (2019-04-16 revision 67580) [x86_64-darwin18]

运行时：$rails new app

/Users/.rbenv/versions/2.3.0/lib/ruby/2.3.0/rubygems/dependency.rb:319:in to_specs': Could not find 'railties' (>= 0.a) among 14 total gem(s) (Gem::LoadError)

在“ GEM_PATH=/Users/.rvm/gems/ruby-2.6.3:/Users/.rvm/gems/ruby-2.6.3@global”中签入，执行gem env以获取更多信息

from/Users/.rbenv/versions/2.3.0/lib/ruby/2.3.0/rubygems/dependency.rb:328:in to_spec'
    from/Users/.rbenv/versions/2.3.0/lib/ruby/2.3.0/rubygems/core_ext/kernel_gem.rb:65:in `gem'

from/Users/.rbenv/versions/2.3.0/bin/rails:22:in `<main>'

任何与Rails相关的代码都不起作用。