RMagick で LoadError

Rails on Ruby にてアプリケーション環境をアップデートしたらエラーが吐いてしまった場合

現象１：RMagick で LoadError

サーバー環境をアップデートした後で発生した問題。

Magick2.so (LoadError)　が出るようになりました。以下がエラーログ

#rails server --bind=0.0.0.0 -d
/home/ec2-user/.gem/ruby/2.0/gems/activesupport-4.1.1/lib/active_support/dependencies.rb:247:in `require': libMagickCore.so.5: cannot open shared object file: No such file or directory - /home/ec2-user/.gem/ruby/2.0/gems/rmagick-2.15.4/lib/RMagick2.so (LoadError)
	from /home/ec2-user/.gem/ruby/2.0/gems/activesupport-4.1.1/lib/active_support/dependencies.rb:247:in `block in require'
	from /home/ec2-user/.gem/ruby/2.0/gems/activesupport-4.1.1/lib/active_support/dependencies.rb:232:in `load_dependency'
	from /home/ec2-user/.gem/ruby/2.0/gems/activesupport-4.1.1/lib/active_support/dependencies.rb:247:in `require'
	from /home/ec2-user/.gem/ruby/2.0/gems/rmagick-2.15.4/lib/rmagick_internal.rb:12:in `<top (required)>'
	from /home/ec2-user/.gem/ruby/2.0/gems/activesupport-4.1.1/lib/active_support/dependencies.rb:247:in `require'
	from /home/ec2-user/.gem/ruby/2.0/gems/activesupport-4.1.1/lib/active_support/dependencies.rb:247:in `block in require'
	from /home/ec2-user/.gem/ruby/2.0/gems/activesupport-4.1.1/lib/active_support/dependencies.rb:232:in `load_dependency'
	from /home/ec2-user/.gem/ruby/2.0/gems/activesupport-4.1.1/lib/active_support/dependencies.rb:247:in `require'
	from /home/ec2-user/.gem/ruby/2.0/gems/rmagick-2.15.4/lib/rmagick.rb:1:in `<top (required)>'
	from /home/ec2-user/.gem/ruby/2.0/gems/bundler-1.9.1/lib/bundler/runtime.rb:76:in `require'
	from /home/ec2-user/.gem/ruby/2.0/gems/bundler-1.9.1/lib/bundler/runtime.rb:76:in `block (2 levels) in require'
	from /home/ec2-user/.gem/ruby/2.0/gems/bundler-1.9.1/lib/bundler/runtime.rb:72:in `each'
	from /home/ec2-user/.gem/ruby/2.0/gems/bundler-1.9.1/lib/bundler/runtime.rb:72:in `block in require'
	from /home/ec2-user/.gem/ruby/2.0/gems/bundler-1.9.1/lib/bundler/runtime.rb:61:in `each'
	from /home/ec2-user/.gem/ruby/2.0/gems/bundler-1.9.1/lib/bundler/runtime.rb:61:in `require'
	from /home/ec2-user/.gem/ruby/2.0/gems/bundler-1.9.1/lib/bundler.rb:134:in `require'
	from /home/ec2-user/app_name/config/application.rb:7:in `<top (required)>'
	from /home/ec2-user/.gem/ruby/2.0/gems/railties-4.1.1/lib/rails/commands/commands_tasks.rb:79:in `require'
	from /home/ec2-user/.gem/ruby/2.0/gems/railties-4.1.1/lib/rails/commands/commands_tasks.rb:79:in `block in server'
	from /home/ec2-user/.gem/ruby/2.0/gems/railties-4.1.1/lib/rails/commands/commands_tasks.rb:76:in `tap'
	from /home/ec2-user/.gem/ruby/2.0/gems/railties-4.1.1/lib/rails/commands/commands_tasks.rb:76:in `server'
	from /home/ec2-user/.gem/ruby/2.0/gems/railties-4.1.1/lib/rails/commands/commands_tasks.rb:40:in `run_command!'
	from /home/ec2-user/.gem/ruby/2.0/gems/railties-4.1.1/lib/rails/commands.rb:17:in `<top (required)>'
	from bin/rails:8:in `require'
	from bin/rails:8:in `<main>'