TypeError array_flip(): Argument #1 ($array) must be of type array, null given

[kbergha]

Description

Hi. I'm getting a type error when trying to edit a single that has a CKE-field.
It's probably related to the setting for "who should see the source button", which I have turned off for everyone.

The field has a custom CKE config, and a custom HTML Purifier config (not sure if these are relevant).

After removing the field, the editing works as expected when adding other field types, like plain text.

Steps to reproduce

CKE config:

Field setup:

Entry type setup:

HTML-purifier config (Default.json):

{
  "AutoFormat.Linkify": true,
  "AutoFormat.RemoveEmpty": true,
  "AutoFormat.RemoveEmpty.RemoveNbsp": true,
  "HTML.Allowed": "a[href],p,ul,ol,li,h2,h3,h4"
}

Then, trying to edit an existing single:

Stacktrace:

TypeError: array_flip(): Argument #1 ($array) must be of type array, null given in /app/vendor/craftcms/ckeditor/src/Field.php:1208
Stack trace:
#0 /app/vendor/craftcms/ckeditor/src/Field.php(1208): array_flip(NULL)
#1 /app/vendor/craftcms/ckeditor/src/Field.php(891): craft\ckeditor\Field->isSourceEditingAllowed(Object(craft\elements\User))
#2 /app/vendor/craftcms/cms/src/base/Field.php(708): craft\ckeditor\Field->inputHtml(NULL, Object(craft\elements\Entry), false)
#3 /app/vendor/craftcms/cms/src/fieldlayoutelements/CustomField.php(406): craft\base\Field->getInputHtml(NULL, Object(craft\elements\Entry))
#4 /app/vendor/craftcms/cms/src/fieldlayoutelements/BaseField.php(365): craft\fieldlayoutelements\CustomField->inputHtml(Object(craft\elements\Entry), false)
#5 /app/vendor/craftcms/cms/src/fieldlayoutelements/CustomField.php(357): craft\fieldlayoutelements\BaseField->formHtml(Object(craft\elements\Entry), false)
#6 /app/vendor/craftcms/cms/src/web/View.php(1885): craft\fieldlayoutelements\CustomField->craft\fieldlayoutelements\{closure}()
#7 /app/vendor/craftcms/cms/src/fieldlayoutelements/CustomField.php(356): craft\web\View->namespaceInputs(Object(Closure), 'fields')
#8 /app/vendor/craftcms/cms/src/models/FieldLayout.php(1013): craft\fieldlayoutelements\CustomField->formHtml(Object(craft\elements\Entry), false)
#9 /app/vendor/craftcms/cms/src/web/View.php(1879): craft\models\FieldLayout->craft\models\{closure}()
#10 /app/vendor/craftcms/cms/src/models/FieldLayout.php(1012): craft\web\View->namespaceInputs(Object(Closure), NULL)
#11 /app/vendor/craftcms/cms/src/controllers/ElementsController.php(1013): craft\models\FieldLayout->createForm(Object(craft\elements\Entry), false, Array)
#12 /app/vendor/craftcms/cms/src/controllers/ElementsController.php(406): craft\controllers\ElementsController->_prepareEditor(Object(craft\elements\Entry), false, true, Object(craft\web\Response), 'main-form', Object(Closure), Object(Closure), Object(Closure))
#13 [internal function]: craft\controllers\ElementsController->craft\controllers\{closure}(Object(craft\web\Response), 'main-form')
#14 /app/vendor/craftcms/cms/src/web/CpScreenResponseFormatter.php(125): call_user_func(Object(Closure), Object(craft\web\Response), 'main-form')
#15 /app/vendor/craftcms/cms/src/web/CpScreenResponseFormatter.php(50): craft\web\CpScreenResponseFormatter->_formatTemplate(Object(craft\web\Response), Object(craft\web\CpScreenResponseBehavior))
#16 /app/vendor/yiisoft/yii2/web/Response.php(1109): craft\web\CpScreenResponseFormatter->format(Object(craft\web\Response))
#17 /app/vendor/craftcms/cms/src/web/Response.php(341): yii\web\Response->prepare()
#18 /app/vendor/yiisoft/yii2/web/Response.php(340): craft\web\Response->prepare()
#19 /app/vendor/yiisoft/yii2/base/Application.php(390): yii\web\Response->send()
#20 /app/web/index.php(12): yii\base\Application->run()
#21 {main}

Additional info

• Craft version: Craft Pro 5.6.1
• PHP version: 8.3.13
• Database driver & version:
• Plugins & versions: CKEditor | 4.5.0