Will the future Volto include a dropdown menu?

Plone Support Customizing Plone
15

I saw this error also. In my case I forgot to add the blocks to dependencies in package.json.

 "addons": [
  "@eeacms/volto-accordion-block",
  "@kitconcept/volto-button-block",
  "@kitconcept/volto-heading-block",
  "@kitconcept/volto-highlight-block",
  "@kitconcept/volto-introduction-block",
  "@kitconcept/volto-separator-block",
  "@kitconcept/volto-slider-block",
  "@kitconcept/volto-light-theme"
],
  "dependencies": {
    "@plone/volto": "workspace:*",
    "@plone/registry": "workspace:*",
    "volto-project-title": "workspace:*",
    "@eeacms/volto-accordion-block": "*",
    "@kitconcept/volto-button-block": "*",
    "@kitconcept/volto-heading-block": "*",
    "@kitconcept/volto-highlight-block": "*",
    "@kitconcept/volto-introduction-block": "*",
    "@kitconcept/volto-separator-block": "*",
    "@kitconcept/volto-slider-block": "*",
    "@kitconcept/volto-light-theme": "*"
  },

I did added them to the volto.config.js also:

const addons = [
  'volto-project-title',
  '@eeacms/volto-accordion-block',
  '@kitconcept/volto-button-block',
  '@kitconcept/volto-heading-block',
  '@kitconcept/volto-highlight-block',
  '@kitconcept/volto-introduction-block',
  '@kitconcept/volto-separator-block',
  '@kitconcept/volto-slider-block',
  '@kitconcept/volto-light-theme'
];