A valid cache entry key is required. Use getAll() to get all table data

I am also facing the same issues.

Based on the comment 🐛 A valid cache entry key is required. Use getAll() to get all table data. Closed: won't fix , I tried few patches from https://www.drupal.org/project/entity_reference_revisions/issues/2799479 🐛 Views doesn't recognize relationship to host Needs review but I am still getting the same issue.

Ran into this too.

I compared the view config export between d7 and d10.3 and the field values were different:

old:

relationships:
  field_ref_author_target_id:
    id: field_ref_author_target_id
    table: node__field_ref_author
    field: field_ref_author_target_id
    relationship: none
    group_type: group
    admin_label: 'Content entity referenced from field_ref_author'
    plugin_id: standard
    required: false
    ui_name: ''
    label: 'Content entity referenced from field_ref_author'
    target_type: node
    field_name: field_ref_author

new:

relationships:
  field_ref_author:
    id: field_ref_author
    table: node__field_ref_author
    field: field_ref_author
    relationship: none
    group_type: group
    admin_label: 'field_ref_author: Content'
    plugin_id: standard
    required: false

The patch sets field to field_name for relationships.

Here's an alternate patch that targets the MigrateViewsRelationship plugin specifically.

Not really sure how the difference affects other types of relationships or which is considered better for inclusion.

But it both seem to work for my use cases.

The changes in this commit https://git.drupalcode.org/project/views_migration/-/commit/2f3d58570609... are relevant to the config key value mismatches.

I have this bug too, no fix, but to debug I use this snippet.
This does allow for the View to load.
In my case after the views_migration the relationship for Flag and VotingApi are not correctly migrated and broken.

# \Drupal\views\Plugin\views\query\QueryPluginBase::getEntityTableInfo

    // Include all relationships.
    foreach ((array) $this->view->relationship as $relationship_id => $relationship) {
      // Start issue #3458813 Comment #6
      if ($relationship->pluginId === 'broken') {
        // Log a warning if the relationship is broken.
        \Drupal::logger('views')->warning('The relationship %relationship is broken.', ['%relationship' => $relationship_id]);
        continue;
      }
      // End issue #3458813 Comment #6
      $table_data = $views_data->get($relationship->definition['base']);
      if (isset($table_data['table']['entity type'])) {