diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
new file mode 100644
index 0000000..52683d9
--- /dev/null
+++ b/.github/workflows/test.yml
@@ -0,0 +1,43 @@
+name: Test
+
+on:
+  - push
+  - pull_request
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        ruby_version:
+          - '2.6'
+          - '2.7'
+          - '3.0'
+        rails_version:
+          - '5.2.6'
+          - '6.0.4'
+          - '6.1.4'
+          - '7.0.0'
+        exclude:
+          - ruby_version: '3.0'
+            rails_version: '5.2.6'
+          - ruby_version: '2.6'
+            rails_version: '7.0.0'
+
+    name: Ruby ${{ matrix.ruby_version }} / Rails ${{ matrix.rails_version }}
+
+    env:
+      RAILS: ${{ matrix.rails_version }}
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Setup Ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: ${{ matrix.ruby_version }}
+          bundler-cache: true
+
+      - name: Test
+        run: bundle exec rspec spec
diff --git a/.gitignore b/.gitignore
index 54cb8bb..b4fb8da 100644
--- a/.gitignore
+++ b/.gitignore
@@ -13,4 +13,7 @@ capybara-*.html
 /spec/tmp/*
 **.orig
 rerun.txt
-pickle-email-*.html
\ No newline at end of file
+pickle-email-*.html
+pkg
+spec/rails
+Gemfile.lock
diff --git a/.travis.yml b/.travis.yml
deleted file mode 100644
index 7b00bc4..0000000
--- a/.travis.yml
+++ /dev/null
@@ -1,8 +0,0 @@
-script: bundle exec rspec spec
-env:
-  matrix:
-    - RAILS=5.0.0
-    - RAILS=5.1.0
-rvm:
-  - 2.2.5
-  - 2.3.1
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 63495ef..458a8a7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,21 @@
 # Changelog
+## [5.0.0] - 2021-11-16
+- Ruby 3 compatibility added #190  | @clinejj
+- Support for a non UTF-8 file when zip uploading #185| @naokirin 
+- Rails 6 supported #183 | @pnghai
+- Drop ruby 2.4 support #192 | @Fivell
+
+
+## [4.2.0] - 2020-02-05
+- generic exception for import added #175 | @linqueta
+
+## [4.1.2] - 2019-12-16
+- allow application/octet-stream content-type #172 | @dmitry-sinina
+- Allow activerecord-import >= 0.27 #171 | @sagium 
+
+## [4.1.1] - 2019-09-20
+- Fix column slicing #168 | @doredesign
+- Handle errors on base #163
 
 ## [4.1.0] - 2019-01-15
 - Upgrade dependencies: `activerecord-import` to >=0.27.1 | @jkowens
diff --git a/Gemfile b/Gemfile
index 57ec576..8dd493e 100644
--- a/Gemfile
+++ b/Gemfile
@@ -6,12 +6,13 @@ gemspec
 
 
 group :test do
-  default_rails_version = "~> 5.1"
+  default_rails_version = "~> 5.2.4"
   rails_version = ENV['RAILS'] || default_rails_version
+  gem 'sassc-rails'
   gem 'rails', rails_version
   gem 'rspec-rails'
   gem 'coveralls', require: false # Test coverage website. Go to https://coveralls.io
-  gem 'sqlite3'
+  gem "sqlite3", "~> 1.4.0"
   gem 'launchy'
   gem 'database_cleaner'
   gem 'capybara'
diff --git a/README.md b/README.md
index c492ee5..357db1b 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # ActiveAdminImport
 
-[![Travis Build   ][build_badge]][build_link]
+[![Build Status   ][build_badge]][build_link]
 [![Coverage Status][coveralls_badge]][coveralls_link]
 [![Code Climate   ][codeclimate_badge]][codeclimate_link]
 [![Gem Version    ][rubygems_badge]][rubygems_link]
@@ -91,8 +91,8 @@ Tool                  | Description
 [rchardet]: https://github.com/jmhodges/rchardet
 [activerecord-import]: https://github.com/zdennis/activerecord-import
 
-[build_badge]: https://travis-ci.org/activeadmin-plugins/active_admin_import.svg?branch=master
-[build_link]: https://travis-ci.org/activeadmin-plugins/active_admin_import
+[build_badge]: https://github.com/activeadmin-plugins/active_admin_import/actions/workflows/test.yml/badge.svg
+[build_link]: https://github.com/activeadmin-plugins/active_admin_import/actions
 [coveralls_badge]: https://coveralls.io/repos/activeadmin-plugins/active_admin_import/badge.svg
 [coveralls_link]: https://coveralls.io/github/activeadmin-plugins/active_admin_import
 [codeclimate_badge]: https://codeclimate.com/github/activeadmin-plugins/active_admin_import/badges/gpa.svg
diff --git a/active_admin_import.gemspec b/active_admin_import.gemspec
index fb2ffce..252c83d 100644
--- a/active_admin_import.gemspec
+++ b/active_admin_import.gemspec
@@ -15,8 +15,8 @@ Gem::Specification.new do |gem|
   gem.name = 'active_admin_import'
   gem.require_paths = ['lib']
   gem.version = ActiveAdminImport::VERSION
-  gem.add_runtime_dependency 'activerecord-import', '~> 0.27'
-  gem.add_runtime_dependency 'rchardet', '~> 1.6'
-  gem.add_runtime_dependency 'rubyzip', '~> 1.2'
-  gem.add_dependency 'activeadmin', '>= 1.0.0.pre2'
+  gem.add_runtime_dependency 'activerecord-import', '>= 0.27'
+  gem.add_runtime_dependency 'rchardet', '>= 1.6'
+  gem.add_runtime_dependency 'rubyzip', '>= 1.2'
+  gem.add_dependency 'activeadmin', '>= 1.0.0'
 end
diff --git a/lib/active_admin_import.rb b/lib/active_admin_import.rb
index 40adf2b..8654626 100644
--- a/lib/active_admin_import.rb
+++ b/lib/active_admin_import.rb
@@ -3,6 +3,7 @@
 require 'active_admin'
 require 'active_admin_import/version'
 require 'active_admin_import/engine'
+require 'active_admin_import/exception'
 require 'active_admin_import/import_result'
 require 'active_admin_import/options'
 require 'active_admin_import/dsl'
diff --git a/lib/active_admin_import/dsl.rb b/lib/active_admin_import/dsl.rb
index 6d4698f..ccfd4ab 100644
--- a/lib/active_admin_import/dsl.rb
+++ b/lib/active_admin_import/dsl.rb
@@ -54,11 +54,14 @@ def active_admin_import(options = {}, &block)
       options.assert_valid_keys(*Options::VALID_OPTIONS)
 
       options = Options.options_for(config, options)
-      params_key = ActiveModel::Naming.param_key(options[:template_object])
 
       collection_action :import, method: :get do
         authorize!(ActiveAdminImport::Auth::IMPORT, active_admin_config.resource_class)
-        @active_admin_import_model = options[:template_object]
+        @active_admin_import_model = if options[:template_object].is_a?(Proc)
+                                       options[:template_object].call
+                                     else
+                                       options[:template_object]
+                                     end
         render template: options[:template]
       end
 
@@ -73,9 +76,15 @@ def active_admin_import(options = {}, &block)
 
       collection_action :do_import, method: :post do
         authorize!(ActiveAdminImport::Auth::IMPORT, active_admin_config.resource_class)
+        options[:controller_context] = self
         _params = params.respond_to?(:to_unsafe_h) ? params.to_unsafe_h : params
         params = ActiveSupport::HashWithIndifferentAccess.new _params
-        @active_admin_import_model = options[:template_object]
+        @active_admin_import_model = if options[:template_object].is_a?(Proc)
+                                       options[:template_object].call
+                                     else
+                                       options[:template_object]
+                                     end
+        params_key = ActiveModel::Naming.param_key(@active_admin_import_model.class)
         @active_admin_import_model.assign_attributes(params[params_key].try(:deep_symbolize_keys) || {})
         # go back to form
         return render template: options[:template] unless @active_admin_import_model.valid?
@@ -92,7 +101,12 @@ def active_admin_import(options = {}, &block)
           else
             instance_exec result, options, &DEFAULT_RESULT_PROC
           end
-        rescue ActiveRecord::Import::MissingColumnError, NoMethodError, ActiveRecord::StatementInvalid, CSV::MalformedCSVError => e
+        rescue ActiveRecord::Import::MissingColumnError,
+               NoMethodError,
+               ArgumentError,
+               ActiveRecord::StatementInvalid,
+               CSV::MalformedCSVError,
+               ActiveAdminImport::Exception => e
           Rails.logger.error(I18n.t('active_admin_import.file_error', message: e.message))
           Rails.logger.error(e.backtrace.join("\n"))
           flash[:error] = I18n.t('active_admin_import.file_error', message: e.message[0..200])
diff --git a/lib/active_admin_import/exception.rb b/lib/active_admin_import/exception.rb
new file mode 100644
index 0000000..7d70a07
--- /dev/null
+++ b/lib/active_admin_import/exception.rb
@@ -0,0 +1,5 @@
+# frozen_string_literal: true
+module ActiveAdminImport
+  class Exception < StandardError
+  end
+end
\ No newline at end of file
diff --git a/lib/active_admin_import/import_result.rb b/lib/active_admin_import/import_result.rb
index 2556a95..9abcc6d 100644
--- a/lib/active_admin_import/import_result.rb
+++ b/lib/active_admin_import/import_result.rb
@@ -33,8 +33,21 @@ def failed_message(options = {})
       limit = options[:limit] || failed.count
       failed.first(limit).map do |record|
         errors = record.errors
-        (errors.full_messages.zip errors.keys.map { |k| record.send k }).map { |ms| ms.join(' - ') }.join(', ')
+        failed_values = attribute_names_for(errors).map do |key|
+          key == :base ? nil : record.public_send(key)
+        end
+        errors.full_messages.zip(failed_values).map { |ms| ms.compact.join(' - ') }.join(', ')
       end.join(' ; ')
     end
+
+    private
+
+    def attribute_names_for(errors)
+      if Gem::Version.new(Rails.version) >= Gem::Version.new('7.0')
+        errors.attribute_names
+      else
+        errors.keys
+      end
+    end
   end
 end
diff --git a/lib/active_admin_import/importer.rb b/lib/active_admin_import/importer.rb
index 9d18e4e..ab337f6 100644
--- a/lib/active_admin_import/importer.rb
+++ b/lib/active_admin_import/importer.rb
@@ -18,7 +18,8 @@ class Importer
       :headers_rewrites,
       :batch_size,
       :batch_transaction,
-      :csv_options
+      :csv_options,
+      :controller_context
     ].freeze
 
     def initialize(resource, model, options)
@@ -37,7 +38,7 @@ def file
     end
 
     def cycle(lines)
-      @csv_lines = CSV.parse(lines.join, @csv_options)
+      @csv_lines = CSV.parse(lines.join, **@csv_options)
       import_result.add(batch_import, lines.count)
     end
 
@@ -70,7 +71,7 @@ def batch_replace(header_key, options)
       end
     end
 
-    # Use it when CSV file contain redundant columns
+    # Use this method when CSV file contains unnecessary columns
     #
     # Example:
     #
@@ -81,16 +82,22 @@ def batch_replace(header_key, options)
     # end
     #
     def batch_slice_columns(slice_columns)
-      use_indexes = []
-      headers.values.each_with_index do |val, index|
-        use_indexes << index if val.in?(slice_columns)
+      # Only set @use_indexes for the first batch so that @use_indexes are in correct
+      # position for subsequent batches
+      unless defined?(@use_indexes)
+        @use_indexes = []
+        headers.values.each_with_index do |val, index|
+          @use_indexes << index if val.in?(slice_columns)
+        end
+        return csv_lines if @use_indexes.empty?
+
+        # slice CSV headers
+        @headers = headers.to_a.values_at(*@use_indexes).to_h
       end
-      return csv_lines if use_indexes.empty?
-      # slice CSV headers
-      @headers = headers.to_a.values_at(*use_indexes).to_h
+
       # slice CSV values
       csv_lines.map! do |line|
-        line.values_at(*use_indexes)
+        line.values_at(*@use_indexes)
       end
     end
 
@@ -109,7 +116,7 @@ def process_file
       batch_size = options[:batch_size].to_i
       File.open(file.path) do |f|
         # capture headers if not exist
-        prepare_headers { CSV.parse(f.readline, @csv_options).first }
+        prepare_headers { CSV.parse(f.readline, **@csv_options).first }
         f.each_line do |line|
           lines << line if line.present?
           if lines.size == batch_size || f.eof?
diff --git a/lib/active_admin_import/model.rb b/lib/active_admin_import/model.rb
index 5927996..f3fde01 100644
--- a/lib/active_admin_import/model.rb
+++ b/lib/active_admin_import/model.rb
@@ -21,6 +21,7 @@ module CONST
         application/csv
         application/vnd.ms-excel
         application/vnd.msexcel
+        application/octet-stream
         text/tsv
         text/x-tsv
         text/tab-separated-values
@@ -102,6 +103,8 @@ def file_path
 
     def encode_file
       data = File.read(file_path)
+      return if data.empty?
+
       File.open(file_path, 'w') do |f|
         f.write(encode(data))
       end
@@ -109,7 +112,7 @@ def encode_file
 
     def unzip_file
       Zip::File.open(file_path) do |zip_file|
-        self.file = Tempfile.new(CONST::TMP_FILE)
+        self.file = Tempfile.new(CONST::TMP_FILE, binmode: true)
         data = zip_file.entries.select(&:file?).first.get_input_stream.read
         file << data
         file.close
diff --git a/lib/active_admin_import/options.rb b/lib/active_admin_import/options.rb
index 53f4a78..3ed1ce8 100644
--- a/lib/active_admin_import/options.rb
+++ b/lib/active_admin_import/options.rb
@@ -26,7 +26,7 @@ module Options
 
     def self.options_for(config, options = {})
       unless options.key? :template_object
-        options[:template_object] = ActiveAdminImport::Model.new
+        options[:template_object] = -> { ActiveAdminImport::Model.new }
       end
 
       {
diff --git a/lib/active_admin_import/version.rb b/lib/active_admin_import/version.rb
index 5f9317a..6affade 100644
--- a/lib/active_admin_import/version.rb
+++ b/lib/active_admin_import/version.rb
@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module ActiveAdminImport
-  VERSION = '4.1.0'
+  VERSION = '5.1.0'
 end
diff --git a/spec/fixtures/files/authors.csv b/spec/fixtures/files/authors.csv
index b523140..a79bff3 100644
--- a/spec/fixtures/files/authors.csv
+++ b/spec/fixtures/files/authors.csv
@@ -1,3 +1,3 @@
-Name,Last name,Birthday
-John,Doe,1986-05-01
-Jane,Roe,1988-11-16
\ No newline at end of file
+Birthday,Name,Last name
+1986-05-01,John,Doe
+1988-11-16,Jane,Roe
diff --git a/spec/fixtures/files/authors_values_exceeded_headers.csv b/spec/fixtures/files/authors_values_exceeded_headers.csv
new file mode 100644
index 0000000..e3ee481
--- /dev/null
+++ b/spec/fixtures/files/authors_values_exceeded_headers.csv
@@ -0,0 +1,3 @@
+Birthday,Name,Last name
+1986-05-01,John,Doe
+1988-11-16,Jane,Roe, exceeded value
\ No newline at end of file
diff --git a/spec/import_result_spec.rb b/spec/import_result_spec.rb
index 918eab4..266ceed 100644
--- a/spec/import_result_spec.rb
+++ b/spec/import_result_spec.rb
@@ -5,17 +5,18 @@
   context 'failed_message' do
     let(:import_result) { ActiveAdminImport::ImportResult.new }
 
-    before do
-      Author.create(name: 'John', last_name: 'Doe')
-      Author.create(name: 'Jane', last_name: 'Roe')
 
+    let(:failed_instances) do
+     [
+         Author.new(last_name: 'Doe').tap {|r| r.errors.add(:last_name,  :taken) },
+         Author.new(name: "", last_name: 'Doe').tap {|r| r.errors.add(:name,  :blank); r.errors.add(:last_name,  :taken)  },
+         Author.new.tap {|r| r.errors.add(:base,  'custom') }
+     ]
+    end
+
+    before do
       @result = double \
-        failed_instances: [
-          # {:last_name=>["has already been taken"]}
-          Author.create(name: 'Jim', last_name: 'Doe'),
-          # {:name=>["can't be blank"], :last_name=>["has already been taken"]}
-          Author.create(name: nil,   last_name: 'Doe')
-        ]
+        failed_instances: failed_instances
     end
 
     it 'should work without any failed instances' do
@@ -26,7 +27,7 @@
       import_result.add(@result, 4)
       expect(import_result.failed_message)
         .to eq(
-          "Last name has already been taken - Doe ; Name can't be blank - , Last name has already been taken - Doe"
+          "Last name has already been taken - Doe ; Name can't be blank - , Last name has already been taken - Doe ; custom"
         )
     end
 
diff --git a/spec/import_spec.rb b/spec/import_spec.rb
index 390edef..cc4db50 100644
--- a/spec/import_spec.rb
+++ b/spec/import_spec.rb
@@ -96,6 +96,38 @@ def upload_file!(name, ext = 'csv')
         end
         include_examples 'successful inserts for author'
       end
+
+      context 'when template object passed like proc' do
+        before do
+          add_post_resource(template_object: -> { ActiveAdminImport::Model.new(author_id: author.id) },
+                            validate: true,
+                            before_batch_import: lambda do |importer|
+                              importer.csv_lines.map! { |row| row << importer.model.author_id }
+                              importer.headers.merge!(:'Author Id' => :author_id)
+                            end
+          )
+
+          visit '/admin/posts/import'
+          upload_file!(:posts_for_author)
+        end
+
+        include_examples 'successful inserts for author'
+
+        context 'after successful import try without file' do
+          let(:after_successful_import_do!) do
+            # reload page
+            visit '/admin/posts/import'
+            # submit form without file
+            find_button('Import').click
+          end
+
+          it 'should render validation error' do
+            after_successful_import_do!
+
+            expect(page).to have_content I18n.t('active_admin_import.no_file_error')
+          end
+        end
+      end
     end
 
     context 'for csv with author name' do
@@ -371,6 +403,20 @@ def upload_file!(name, ext = 'csv')
             end
           end
         end
+
+        context 'when zipped with Win1251 file' do
+          let(:options) do
+            attributes = { force_encoding: :auto }
+            { template_object: ActiveAdminImport::Model.new(attributes) }
+          end
+          it 'should import file' do
+            with_zipped_csv(:authors_win1251_win_endline) do
+              upload_file!(:authors_win1251_win_endline, :zip)
+              expect(page).to have_content 'Successfully imported 2 authors'
+              expect(Author.count).to eq(2)
+            end
+          end
+        end
       end
 
       context 'with different header attribute names' do
@@ -410,6 +456,36 @@ def upload_file!(name, ext = 'csv')
           expect(Author.count).to eq(2)
         end
       end
+
+      context 'with empty csv and auto detect encoding' do
+        let(:options) do
+          attributes = { force_encoding: :auto }
+          { template_object: ActiveAdminImport::Model.new(attributes) }
+        end
+
+        before do
+          upload_file!(:empty)
+        end
+
+        it 'should render warning' do
+          expect(page).to have_content I18n.t('active_admin_import.file_empty_error')
+          expect(Author.count).to eq(0)
+        end
+      end
+
+      context 'with csv which has exceeded values' do
+        before do
+          upload_file!(:authors_values_exceeded_headers)
+        end
+
+        it 'should render warning' do
+          # 5 columns: 'birthday, name, last_name, created_at, updated_at'
+          # 6 values: '"1988-11-16", "Jane", "Roe", " exceeded value", datetime, datetime'
+          msg = 'Number of values (6) exceeds number of columns (5)'
+          expect(page).to have_content I18n.t('active_admin_import.file_error', message: msg)
+          expect(Author.count).to eq(0)
+        end
+      end
     end
 
     context 'with callback procs options' do
@@ -430,15 +506,40 @@ def upload_file!(name, ext = 'csv')
         upload_file!(:authors)
         expect(Author.count).to eq(2)
       end
+
+      context 'when the option before_import raises a ActiveAdminImport::Exception' do
+        let(:options) { { before_import: ->(_) { raise ActiveAdminImport::Exception, 'error message' } } }
+
+        before { upload_file!(:authors) }
+
+        it 'should show error' do
+          expect(page).to have_content I18n.t('active_admin_import.file_error', message: 'error message')
+          expect(Author.count).to eq(0)
+        end
+      end
+
+      context 'when the option before_batch_import raises a ActiveAdminImport::Exception' do
+        let(:options) { { before_batch_import: ->(_) { raise ActiveAdminImport::Exception, 'error message' } } }
+
+        before { upload_file!(:authors) }
+
+        it 'should show error' do
+          expect(page).to have_content I18n.t('active_admin_import.file_error', message: 'error message')
+          expect(Author.count).to eq(0)
+        end
+      end
     end
   end
 
   context "with slice_columns option" do
+    let(:batch_size) { 2 }
+
     before do
       add_author_resource template_object: ActiveAdminImport::Model.new,
                           before_batch_import: lambda { |importer|
                             importer.batch_slice_columns(slice_columns)
-                          }
+                          },
+                          batch_size: batch_size
       visit "/admin/authors/import"
       upload_file!(:authors)
     end
@@ -446,13 +547,23 @@ def upload_file!(name, ext = 'csv')
     context "slice last column and superfluous column" do
       let(:slice_columns) { %w(name last_name not_existing_column) }
 
-      it "should not fill `birthday` column" do
-        expect(Author.pluck(:name, :last_name, :birthday)).to match_array(
-          [
-            ["Jane", "Roe", nil],
-            ["John", "Doe", nil]
-          ]
-        )
+      shared_examples_for "birthday column removed" do
+        it "should not fill `birthday` column" do
+          expect(Author.pluck(:name, :last_name, :birthday)).to match_array(
+            [
+              ["Jane", "Roe", nil],
+              ["John", "Doe", nil]
+            ]
+          )
+        end
+      end
+
+      it_behaves_like "birthday column removed"
+
+      context "when doing more than one batch" do
+        let(:batch_size) { 1 }
+
+        it_behaves_like "birthday column removed"
       end
     end
 
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index aded259..c8fd58e 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -20,6 +20,7 @@
 require 'active_model'
 # require ActiveRecord to ensure that Ransack loads correctly
 require 'active_record'
+require 'action_view'
 require 'active_admin'
 ActiveAdmin.application.load_paths = [ENV['RAILS_ROOT'] + '/app/admin']
 require ENV['RAILS_ROOT'] + '/config/environment.rb'
diff --git a/tasks/test.rake b/tasks/test.rake
index 8def1e9..6699224 100644
--- a/tasks/test.rake
+++ b/tasks/test.rake
@@ -3,5 +3,5 @@ desc 'Creates a test rails app for the specs to run against'
 task :setup do
   require 'rails/version'
   system('mkdir spec/rails') unless File.exist?('spec/rails')
-  system "bundle exec rails new spec/rails/rails-#{Rails::VERSION::STRING} -m spec/support/rails_template.rb --skip-spring  --skip-turbolinks"
+  system "bundle exec rails new spec/rails/rails-#{Rails::VERSION::STRING} -m spec/support/rails_template.rb --skip-spring  --skip-turbolinks  --skip-bootsnap"
 end