Ruby cannot load such file - active_support/core_ext/object/blank
I face the 'sunspot_rails-2.1.0' issue while upgrade the ruby version ruby 2.2 to ruby 2.5 for rails 4.2 and here I would like to share with you which has worked for me.
"LoadError: no such file to load -- active_support/core_ext/object/to_json"