When I try to go to the Structure > Webforms > Settings and Webforms I am getting the following error. I tried the $ drush webform-repair command, but that doesn't work. My Drupal version is 8.6.4.

The website encountered an unexpected error. Please try again later. TypeError: Argument 4 passed to Drupal\webform\EntitySettings\WebformEntitySettingsBaseForm::appendBehaviors() must be of the type array, null given, called in /Applications/MAMP/htdocs/ubci+webform/modules/webform/src/EntitySettings/WebformEntitySettingsGeneralForm.php on line 274 in Drupal\webform\EntitySettings\WebformEntitySettingsBaseForm->appendBehaviors() (line 104 of modules/webform/src/EntitySettings/WebformEntitySettingsBaseForm.php).

And I am getting another error when I try to download the results on Webforms > Download.

The website encountered an unexpected error. Please try again later. Error: Unsupported operand types in Drupal\webform\Form\WebformResultsExportForm->buildForm() (line 57 of modules/webform/src/Form/WebformResultsExportForm.php). Drupal\webform\Form\WebformResultsExportForm->buildForm(Array, Object, Object)

  • In case you have not tried it: Goto Configuration/Development/Performance and clear the cache. Also since you are using Webform... be sure to use composer and see if the Webform and it's requirements are up to date.
    – DStrider
    Sep 24, 2019 at 19:31

2 Answers 2


I found the solution on the maintainer's blog: https://www.jrockowitz.com/blog/managing-webform-configuration. Go to admin/structure/webform/config/advanced and click 'Repair configuration'.

Repairing admin configuration and webform settings

If you happen upon some webform configuration that is outdated, you can run the drush webform:repair command or click the 'Repair configuration' via the admin UI under that 'Advanced' configuration tab (admin/structure/webform/config/advanced)

  • this fixed the issue for me today
    – Jonatas CD
    Mar 13 at 16:14

In my case, I was working on a migrated site and didn't have the webform.settings config.

To fix:

  1. Grab config from an existing site: /admin/config/development/configuration/single/export
  2. Import the config to current site: /admin/config/development/configuration/single/import

I had some errors about themes not being present, so I had to create dummy themes, install them, then uninstall them before the config import would work.

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