How to remove variables via the config editor?

I’m totally new to Drupal, so I may be asking a trivial question here. While developing a new website in Drupal9, I’m trying to install the CERN Full Html module, but I’m getting the following error message:

“Unable to install Cern Full Html Format, editor.editor.cern_full_html, filter.format.cern_full_html already exist in active configuration”

I’ve tried removing these two variables from my active configuration via the config editor, but when deleting any of the two, I’m getting the error: “The website encountered an unexpected error. Please try again later.”

Any ideas how to fix this issue ? Thanks in advance

Dear Michael

This short guide is not for beginners, use it at your own risk. Read it carefully first.
I will try to explain several concepts before suggesting a possible solution.

  1. Precedence in “symfony/drupal”, let’s review editor.editor.cern_full_html we have 3 sentences, separated by 2 dots, it means that cern_full_html is the inheritance of 2 predecessors. Therefore you cannot delete cern_full_html directly, you must “unlink” it first. In many cases “unlink” is not enough, you need to run something else. We cover both cases.

  2. Where is located “cern_full_html”? it is text format contains filters that change the display of user input. It means that all nodes/objects/classes that you create/edit using this format will be affected by any changes.

  3. Look at https://<your-site>/admin/config/content/formats
    Menu: Configuration=>Content authoring =>Text formats and editors

  4. Before continuing, I don’t know your site, I will suggest an intermediate step to test

Click under the “Add text format” button and create a new one item

a-)Name: test-my, take note at right for the machine name, in my case test_my
b-)Set roles
c-)select an item under the “Text editor” list
d-)save the configuration
e-) save

In your configuration you have 2 news items “editor.editor.test_my” and “filter.format.test_my”. if you try to delete the new configuration, you will get the same error message.

Nothing new so far… Let’s go to the pizza cheese

5-) goto again under https://<your-site>/admin/config/content/formats
6-) click under “configure” button
7-) in the text editor list select “none”
8 -) save
10-) If you check your configuration “editor.editor.test_my”, it’s gone. First unlink.
11-) goto again under https://<your-site>/admin/config/content/formats
12-) at the right “configure” button have more options select “Disable”, click “Disable” (unlink!!! but not delete)
13-) save

14-) install two modules “Devel” and “Devel PHP” (how to install? check forum topics)
15-) clear cache
16-) goto to https://<your-website>/devel/php
17-) copy “\Drupal::configFactory()->getEditable(‘filter.format.test_my’)->delete();” look over the machine name(test_my), just remember the step 4.a)

18-) click over the execute button
19-) Done!!! your configuration file is deleted!!!

If you have any questions do not hesitate to write me.

best regards

Hi Michael

I am just following up on this; did Guillermo’s advice above help you?

If you are still facing issues, please let us know.


Hello Joachim,

The original issue seems to be solved; i could install the CERN modules that I wanted. However, I’m now facing a new problem, i.e. when I try to add a CERN Landing Page to my webpage content, I’m getting the following general error: “The website encountered an unexpected error. Please try again later.” Looking at the log files, I see what is shown in the screenshot below. Any hints on how to solve this one ?

Thanks a lot,

Hi Michael

We are working on a guide on how to resolve this.

We will apply the fix for you on in the meantime.


Great ! Thanks a lot for the help.