Your Redmine stack was released long ago, and the Ruby shipped as you detailed is
2.0.0. Therefore, the version of the nokogiri gem you are trying to install can not be used because it's a previous version to the required one,
2.1.0, as stated in those logs, and in https://rubygems.org/gems/nokogiri
Which steps did you follow in order to encounter this? Did you delete your
If that was the case, you can try locking the version of that gem in the
gemfile via doing something like this:
gem 'nokogiri', '18.104.22.168'
which is the latest version compatible with Ruby
We’ll be looking forward to receiving your reply.