Programmatically added block doesn't appear in block admin page First of all, this is not a duplicate of this question, as I can't see my block even though I click Place Block.

Below is my block class. To the best of my knowledge, it should appear in the list, but it doesn't. What am I doing wrong? There is another block class, and that can be discovered.

&lt;?php

namespace Drupal\tcmb\Plugin\Block;

use Drupal\Core\Block\BlockBase;

/**
 * Provides a 'Tcmb Currency' block.
 *
 * @Block(
 *  id = "tcmb_currency_block",
 *  admin_label = @Translation("Tcmb: currency"),
 *  category = @Translation("Tcmb")
 * )
 */

/**
 * Display TCMB currencies as a block.
 */
class TcmbCurrencyBlock extends BlockBase {
The problem was me creating a document block above the class, creating an interference between the class and annotation. Another lesson learned the hard way.