This patch contains fixes specified devised for BWMA migraiton from D7 to D9. This can be removed once the migraiton is over.

bwma-migration-d9-core.patch

--- a/core/modules/field/src/Plugin/migrate/field/d7/EntityReference.php
+++ b/core/modules/field/src/Plugin/migrate/field/d7/EntityReference.php
@@ -32,4 +32,15 @@
     ];
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function getFieldWidgetMap() {
+    $map = parent::getFieldWidgetMap() + [
+      'inline_entity_form_single' => 'inline_entity_form_simple',
+      'inline_entity_form' => 'inline_entity_form_complex',
+    ];
+    return $map;
+  }
+
 }

--- a/core/modules/field/src/Plugin/migrate/process/d7/FieldInstanceSettings.php
+++ b/core/modules/field/src/Plugin/migrate/process/d7/FieldInstanceSettings.php
@@ -126,6 +126,18 @@
           'uuid' => '',
         ];
         break;
+      case 'media_generic':
+        $settings = $instance_settings;
+        if (isset($instance_settings['default_image']) && $instance_settings['default_image'] === 0) {
+          $settings['default_image'] = [
+            'alt' => '',
+            'title' => '',
+            'width' => NULL,
+            'height' => NULL,
+            'uuid' => '',
+          ];
+        }
+        break;
 
       default:
         $settings = $instance_settings;
--- a/core/modules/field/src/Plugin/migrate/process/d7/FieldSettings.php
+++ b/core/modules/field/src/Plugin/migrate/process/d7/FieldSettings.php
@@ -44,6 +44,10 @@
       case 'user_reference':
         $value['target_type'] = 'user';
         break;
+      case 'entityreference':
+        if ($value['target_type'] == 'profile2') {
+          $value['target_type'] = 'profile';
+        }
 
       default:
         break;
--- a/core/modules/file/src/Plugin/migrate/field/d6/FileField.php
+++ b/core/modules/file/src/Plugin/migrate/field/d6/FileField.php
@@ -38,6 +38,7 @@
       'image_plain' => 'image',
       'image_nodelink' => 'image',
       'image_imagelink' => 'image',
+      'file_download_link' => 'generic_media_link',
     ];
   }