Error installing json 1.8.3 with ruby 2.4

In Gemfile.lock

json (~>1.8.3)

then do the

bundle update

I ran into the same issue recently as well, try and see if there's a newer version of whatever gem you're using that depends on json 1.8.3. This is happening because Ruby 2.4 unified Fixnum and Bignum into Integer. If you're able to upgrade to json 1.8.5 or higher, it should help fix your problems.

You could also try and update the gem you're using and try to relax the version constraints (I've found this to work with a lot of projects, but not all) like so:

gem 'json', '>= 1.8'

Try removing the Gemfile.lock and running the bundle command again. It should be using a different version of json (ie. 1.8.6) without a problem.