# I am using ruby version 2.3.8 and rails version 5.2.6 to develop my application , since yesterday i am getting the error , i tried to find the occurrence of this NOKOGIRI::HTML4 in my application but i didn't find any of the occurrence like this

**URL:** <https://www.ruby-forum.com/t/i-am-using-ruby-version-2-3-8-and-rails-version-5-2-6-to-develop-my-application-since-yesterday-i-am-getting-the-error-i-tried-to-find-the-occurrence-of-this-nokogiri-html4-in-my-application-but-i-didnt-find-any-of-the-occurrence-like-this/263852>\
**Category:** Uncategorized\
**Created:** [May 15, 2023, 7:25am UTC](https://www.ruby-forum.com/t/i-am-using-ruby-version-2-3-8-and-rails-version-5-2-6-to-develop-my-application-since-yesterday-i-am-getting-the-error-i-tried-to-find-the-occurrence-of-this-nokogiri-html4-in-my-application-but-i-didnt-find-any-of-the-occurrence-like-this/263852 "2023-05-15T07:25:16Z")\
**Posts on this page:** 9\
**Page:** 1

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**Author:** ![knb1](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/f6c823/32.png) [@knb1](https://www.ruby-forum.com/u/knb1)\
**Post date:** [May 15, 2023, 7:25am UTC](https://www.ruby-forum.com/t/i-am-using-ruby-version-2-3-8-and-rails-version-5-2-6-to-develop-my-application-since-yesterday-i-am-getting-the-error-i-tried-to-find-the-occurrence-of-this-nokogiri-html4-in-my-application-but-i-didnt-find-any-of-the-occurrence-like-this/263852/1 "2023-05-15T07:25:16Z")

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uninitialized constant Nokogiri::HTML4  
Did you mean? Nokogiri::HTML (NameError)

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**Author:** ![robert-b](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/54ee81/32.png) [@robert-b](https://www.ruby-forum.com/u/robert-b)\
**Post date:** [May 15, 2023, 7:25am UTC](https://www.ruby-forum.com/t/i-am-using-ruby-version-2-3-8-and-rails-version-5-2-6-to-develop-my-application-since-yesterday-i-am-getting-the-error-i-tried-to-find-the-occurrence-of-this-nokogiri-html4-in-my-application-but-i-didnt-find-any-of-the-occurrence-like-this/263852/2 "2023-05-15T07:25:32Z")

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Hi Krushna,

It seems like you’re trying to use a non-existent constant `Nokogiri::HTML4`. Instead, you should be using `Nokogiri::HTML`. Please update your code with the correct constant and the issue should be resolved.

Best,  
Bobby the Bot

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**Author:** ![knb1](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/f6c823/32.png) [@knb1](https://www.ruby-forum.com/u/knb1)\
**Post date:** [May 15, 2023, 7:27am UTC](https://www.ruby-forum.com/t/i-am-using-ruby-version-2-3-8-and-rails-version-5-2-6-to-develop-my-application-since-yesterday-i-am-getting-the-error-i-tried-to-find-the-occurrence-of-this-nokogiri-html4-in-my-application-but-i-didnt-find-any-of-the-occurrence-like-this/263852/3 "2023-05-15T07:27:13Z")

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i already tried this , but i wont found any of the occurance of the Nokogiri::HTML

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**Author:** ![jleffert](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/a4c791/32.png) [@jleffert](https://www.ruby-forum.com/u/jleffert)\
**Post date:** [May 15, 2023, 11:09pm UTC](https://www.ruby-forum.com/t/i-am-using-ruby-version-2-3-8-and-rails-version-5-2-6-to-develop-my-application-since-yesterday-i-am-getting-the-error-i-tried-to-find-the-occurrence-of-this-nokogiri-html4-in-my-application-but-i-didnt-find-any-of-the-occurrence-like-this/263852/4 "2023-05-15T23:09:43Z")

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A dependency broke. I ran into this same issue trying to deploy my app.

I had to lock the Loofah gem. It appears they released a version requiring a newer version of Nokogiri, but didn’t update the dependency requirement.

This fixed my code in the Gemfile:

`gem 'loofah', '~>2.19.1'`

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**Author:** ![knb1](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/f6c823/32.png) [@knb1](https://www.ruby-forum.com/u/knb1)\
**Post date:** [May 16, 2023, 5:34am UTC](https://www.ruby-forum.com/t/i-am-using-ruby-version-2-3-8-and-rails-version-5-2-6-to-develop-my-application-since-yesterday-i-am-getting-the-error-i-tried-to-find-the-occurrence-of-this-nokogiri-html4-in-my-application-but-i-didnt-find-any-of-the-occurrence-like-this/263852/5 "2023-05-16T05:34:28Z")

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Thanks for the help. This work for me.

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**Author:** ![channaly](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/87869e/32.png) [@channaly](https://www.ruby-forum.com/u/channaly)\
**Post date:** [June 21, 2023, 10:55am UTC](https://www.ruby-forum.com/t/i-am-using-ruby-version-2-3-8-and-rails-version-5-2-6-to-develop-my-application-since-yesterday-i-am-getting-the-error-i-tried-to-find-the-occurrence-of-this-nokogiri-html4-in-my-application-but-i-didnt-find-any-of-the-occurrence-like-this/263852/6 "2023-06-21T10:55:44Z")

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Upgrade from 6.0.4.2 to 6.1.7.3 raised this issue. By adding gem ‘loofah’, ‘~\>2.19.1’ fixed the problem.

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**Author:** ![komawakenna](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/8e7dd6/32.png) [@komawakenna](https://www.ruby-forum.com/u/komawakenna)\
**Post date:** [July 30, 2023, 5:50pm UTC](https://www.ruby-forum.com/t/i-am-using-ruby-version-2-3-8-and-rails-version-5-2-6-to-develop-my-application-since-yesterday-i-am-getting-the-error-i-tried-to-find-the-occurrence-of-this-nokogiri-html4-in-my-application-but-i-didnt-find-any-of-the-occurrence-like-this/263852/7 "2023-07-30T17:50:16Z")

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thanks for help really!

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**Author:** ![andrewfromx](https://www.ruby-forum.com/user_avatar/www.ruby-forum.com/andrewfromx/32/3249_2.png) [@andrewfromx](https://www.ruby-forum.com/u/andrewfromx)\
**Post date:** [August 20, 2023, 6:57pm UTC](https://www.ruby-forum.com/t/i-am-using-ruby-version-2-3-8-and-rails-version-5-2-6-to-develop-my-application-since-yesterday-i-am-getting-the-error-i-tried-to-find-the-occurrence-of-this-nokogiri-html4-in-my-application-but-i-didnt-find-any-of-the-occurrence-like-this/263852/8 "2023-08-20T18:57:03Z")

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same problem but which Gem was including it? I ran:

grep -R “HTML4” /Users/aa/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/

`rails-dom-testing-2.2.0`

for me.

Update: nope, it was gem ‘loofah’, ‘2.21.3’ that fixed it.

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**Author:** ![Khaled9447](https://www.ruby-forum.com/user_avatar/www.ruby-forum.com/khaled9447/32/3301_2.png) [@Khaled9447](https://www.ruby-forum.com/u/Khaled9447)\
**Post date:** [January 11, 2024, 10:25am UTC](https://www.ruby-forum.com/t/i-am-using-ruby-version-2-3-8-and-rails-version-5-2-6-to-develop-my-application-since-yesterday-i-am-getting-the-error-i-tried-to-find-the-occurrence-of-this-nokogiri-html4-in-my-application-but-i-didnt-find-any-of-the-occurrence-like-this/263852/9 "2024-01-11T10:25:04Z")

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This worked for me, thanks a lot!