diff --git a/modules/ckeditor5_plugin_pack_font/src/Plugin/CKEditor5Plugin/FontColor.php b/modules/ckeditor5_plugin_pack_font/src/Plugin/CKEditor5Plugin/FontColor.php
--- a/modules/ckeditor5_plugin_pack_font/src/Plugin/CKEditor5Plugin/FontColor.php	(revision 724803e56c7685e6a4eabbc5fe4d7031c0551c46)
+++ b/modules/ckeditor5_plugin_pack_font/src/Plugin/CKEditor5Plugin/FontColor.php	(revision b2bbf93e1fbaf311cb55ccf473b9ecf11e7d6ac4)
@@ -54,7 +54,7 @@
     $colors = $this->configuration['colors'];
     if ($form_state->isRebuilding()) {
       $userInput = $form_state->getUserInput();
-      $colors = $userInput['editor']['settings']['plugins']['ckeditor5_plugin_pack_font__font_color']['custom_colors_wrapper'];
+      $colors = $userInput['editor']['settings']['plugins']['ckeditor5_plugin_pack_font__font_color']['custom_colors_wrapper'] ?? [];
     }

     foreach ($colors as $colorId => $option) {
===================================================================
diff --git a/modules/ckeditor5_plugin_pack_highlight/src/Plugin/CKEditor5Plugin/Highlight.php b/modules/ckeditor5_plugin_pack_highlight/src/Plugin/CKEditor5Plugin/Highlight.php
--- a/modules/ckeditor5_plugin_pack_highlight/src/Plugin/CKEditor5Plugin/Highlight.php	(revision 724803e56c7685e6a4eabbc5fe4d7031c0551c46)
+++ b/modules/ckeditor5_plugin_pack_highlight/src/Plugin/CKEditor5Plugin/Highlight.php	(revision b2bbf93e1fbaf311cb55ccf473b9ecf11e7d6ac4)
@@ -99,7 +99,7 @@
     $options = $this->configuration['options'];
     if ($form_state->isRebuilding()) {
       $userInput = $form_state->getUserInput();
-      $options = $userInput['editor']['settings']['plugins']['ckeditor5_plugin_pack_highlight__highlight']['custom_marker_wrapper'];
+      $options = $userInput['editor']['settings']['plugins']['ckeditor5_plugin_pack_highlight__highlight']['custom_marker_wrapper'] ?? [];
     }

     foreach ($options as $markerId => $option) {
===================================================================
diff --git a/modules/ckeditor5_plugin_pack_text_transformation/src/Plugin/CKEditor5Plugin/TextTransformation.php b/modules/ckeditor5_plugin_pack_text_transformation/src/Plugin/CKEditor5Plugin/TextTransformation.php
--- a/modules/ckeditor5_plugin_pack_text_transformation/src/Plugin/CKEditor5Plugin/TextTransformation.php	(revision 724803e56c7685e6a4eabbc5fe4d7031c0551c46)
+++ b/modules/ckeditor5_plugin_pack_text_transformation/src/Plugin/CKEditor5Plugin/TextTransformation.php	(revision b2bbf93e1fbaf311cb55ccf473b9ecf11e7d6ac4)
@@ -152,7 +152,7 @@
     $regexArr = $this->configuration['extra_regex_transformations'];
     if ($form_state->isRebuilding()) {
       $userInput = $form_state->getUserInput();
-      $regexArr = $userInput['editor']['settings']['plugins']['ckeditor5_plugin_pack_text_transformation__text_transformation']['regex_transformation_wrapper'];
+      $regexArr = $userInput['editor']['settings']['plugins']['ckeditor5_plugin_pack_text_transformation__text_transformation']['regex_transformation_wrapper'] ?? [];
     }

     foreach ($regexArr as $regexId => $regex) {