Changed
ActionDispatch::ParamsParser::DEFAULT_PARSERS.delete(Mime::XML) if Rails::VERSION::STRING.to_i
to
ActionDispatch::ParamsParser::DEFAULT_PARSERS.delete(Mime::XML)
because although it worked, it was obviously redundant. This is the result of an urgent security fix:
http://www.securityweek.com/ruby-rails-releases-extremely-critical-security-fixes-–-exploit-code-en-route