ZombiMorgan

<?php
function projects_node_project_form_validate(&$form, FormStateInterface $form_state) {
//  $project = $form_state->getFormObject()->getEntity();
  $value = $form_state->getValue(['field_value', '0', 'value']);
  $sum = 0;
//  $status = $form_state->getValue(['field_status', '0', 'value']);

  foreach ($form_state->getValue('field_investors') as $index => $item)
    if (is_numeric($index)) {
      $sum += $item['subform']['field_contribution']['0']['value'] + $item['subform']['field_contribution_over']['0']['value'];

ZombiMorgan

<?php

namespace Drupal\projects\Plugin\Block;

use Drupal\Component\Serialization\Json;
use Drupal\Core\Block\Annotation\Block;
use Drupal\Core\Block\BlockBase;
use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
use Symfony\Component\DependencyInjection\ContainerInterface;