our site is throwing up the following error:

A list field (field_type) with existing data cannot have its keys changed. in list_field_update_forbid() (line 363 of /modules/field/modules/list/list.module).

I've already researched and found on the drupal developer site a documentation about this error: https://drupal.org/node/1294264

But honestly I don't know what to do.

Has anybody an idea?

Thank you and best wishes


3 Answers 3


Try to delete the specified config file:

drush config-delete <name of the config to delete>

and than import the config again:

drush cim

  • 1
    Don't try this with field storage configs!
    – oknate
    Jul 15, 2020 at 16:10
  • 1
    @oknate, I've gotten this error with a field storage config. Any recommendations?
    – Kellen
    Sep 2, 2020 at 19:04

If anyone else comes across this, Double check the "Allowed Values" of the features field in question against what is listed in the site you are overriding. In my case, fixing the discrepancy there sorted everything out. Essentially, the values in the features export didn't include an option that was added, and referenced in the DB by a node.


Expanding Michiel's answer... This worked for me in Drupal 8, assuming you've got your config exported before making changes. I was able to edit the config file with new Allowed Values then delete and re-import. Old nodes retained the previous values, new and edited nodes get the new choices.

Edit the config file.

Then delete the config with drush

drush config-delete <name of the config to delete>

Then import the config again:

drush cim

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