>>> [!note] Migrated issue <!-- Drupal.org comment --> <!-- Migrated from issue #3581055. --> Reported by: [bisonbleu](https://www.drupal.org/user/549974) Related to !74 >>> <h3 id="summary-problem-motivation">Problem/Motivation</h3> <p>When trying to replicate the <strong>Calculated entity field</strong> model (<a href="https://ecaguide.org/library/simple/calculated_entity_field/">eca_lib_0022</a>), the Tamper: Math plugin <strong>Value</strong> field does not accept tokens such as <code>[node:field_length:value]</code> or <code>[node:field_width:value]</code> for that matter, it refuses to save the form and displays an error.</p> <p>Strangely, if one opens the recipe's model with WM, the Value field appears to be empty but it is possible to save the model.</p> <p><img src="https://www.drupal.org/files/issues/2026-03-23/tamper-math--value-field.jpg" alt="WM UI"></p> > Related issue: [Issue #3582649](https://www.drupal.org/node/3582649)