discourse/discourse · error · Error

[FormKit]: the @data property expects a POJO.

Error message

[FormKit]: the @data property expects a POJO.

What it means

Error "[FormKit]: the @data property expects a POJO." thrown in discourse/discourse.

Source

Thrown at frontend/discourse/app/form-kit/lib/fk-form-data.js:51

  @tracked patches = [];

  /**
   * The inverse patches to be applied, useful for rollback.
   * @type {Array}
   */
  @tracked inversePatches = [];

  /**
   * Creates an instance of Changeset.
   * @param {any} data - The initial data.
   */
  constructor(data) {
    try {
      this.data = produce(data, () => {});
      this.draftData = produce(data, () => {});
    } catch (e) {
      if (e.message.includes("[Immer]")) {
        throw new Error("[FormKit]: the @data property expects a POJO.", {
          cause: e,
        });
      }
    }
  }

  /**
   * Checks if the changeset is valid.
   * @return {boolean} True if there are no errors.
   */
  get isValid() {
    return Object.keys(this.errors).length === 0;
  }

  /**
   * Checks if the changeset is invalid.
   * @return {boolean} True if there are errors.
   */

View on GitHub (pinned to 1b2d7253e8)

When it happens

Trigger: Thrown at frontend/discourse/app/form-kit/lib/fk-form-data.js:51 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of discourse/discourse@1b2d7253e8 (2026-08-26). Data as JSON: /api/errors/795367a60348a031. Report an issue: GitHub.