Argument 1 passed to EntityViewBuilder must implement interface, null given

In my Drupal project I have this error:

Recoverable fatal error: Argument 1 passed to Drupal\Core\Entity\EntityViewBuilder::view() must implement interface Drupal\Core\Entity\EntityInterface, null given, called in /Users/team1/workspace/ga_p/modules/field_collection/src/Plugin/Field/FieldFormatter/FieldCollectionItemsFormatter.php on line 33 and defined in Drupal\Core\Entity\EntityViewBuilder->view() (line 110 of core/lib/Drupal/Core/Entity/EntityViewBuilder.php). I do not know if it's from having created multiple fields (fieldCollections)

But I do not know how to remove this error.

Drupal Version: 8.3.4

Try this patch

diff --git a/src/Plugin/Field/FieldType/FieldCollection.php b/src/Plugin/Field/FieldType/FieldCollection.php
index 8721220..c5335be 100644
--- a/src/Plugin/Field/FieldType/FieldCollection.php
+++ b/src/Plugin/Field/FieldType/FieldCollection.php
@@ -183,19 +183,15 @@ class FieldCollection extends EntityReferenceItem {
   public function preSave() {

     if ($field_collection_item = $this->getFieldCollectionItem()) {
-      // TODO: Handle node cloning
-      /*
-      if (!empty($host_entity->is_new) && empty($entity->is_new)) {
+      $host = $this->getEntity();
+
+      // Handle node cloning
+      if($host->isNew() && !$field_collection_item->isNew()) {
         // If the host entity is new but we have a field_collection that is not
         // new, it means that its host is being cloned. Thus we need to clone
         // the field collection entity as well.
-        $new_entity = clone $entity;
-        $new_entity->target_id = NULL;
-        $new_entity->revision_id = NULL;
-        $new_entity->is_new = TRUE;
-        $entity = $new_entity;
+        $field_collection_item = $field_collection_item->createDuplicate();
       }
-      */

       // TODO: Handle deleted items
       /*
@@ -231,11 +227,10 @@ class FieldCollection extends EntityReferenceItem {
       }
       */

-      $this->newHostRevision = $this->getEntity()->isNewRevision();
+      $this->newHostRevision = $host->isNewRevision();

       // If the host entity is saved as new revision, do the same for the item.
       if ($this->newHostRevision) {
-        $host = $this->getEntity();

         $field_collection_item->setNewRevision();

diff --git a/src/Plugin/Field/FieldWidget/FieldCollectionEmbedWidget.php b/src/Plugin/Field/FieldWidget/FieldCollectionEmbedWidget.php
index 4d6ae09..800383f 100644
--- a/src/Plugin/Field/FieldWidget/FieldCollectionEmbedWidget.php
+++ b/src/Plugin/Field/FieldWidget/FieldCollectionEmbedWidget.php
@@ -104,9 +104,8 @@ class FieldCollectionEmbedWidget extends WidgetBase {
   protected function formMultipleElements(FieldItemListInterface $items, array &$form, FormStateInterface $form_state) {
     // We don't want to render empty items on field collection fields
     // unless a) the field collection is empty ; b) the form is rebuilding,
-    // which means that the user clicked on "Add another item"; or
-    // c) we are creating a new entity.
-    if ((count($items) > 0) && !$form_state->isRebuilding() && !$items->getEntity()->isNew()) {
+    // which means that the user clicked on "Add another item"
+    if ((count($items) > 0) && !$form_state->isRebuilding()) {
       $field_name = $this->fieldDefinition->getName();
       $cardinality = $this->fieldDefinition->getFieldStorageDefinition()->getCardinality();
       $parents = $form['#parents'];

mentioned here.