mattermost-community/focalboard · error

cannot create card: %w

Error message

cannot create card: %w

What it means

CreateCard converts the Card model into a Block and inserts it via InsertBlocksAndNotify. This error wraps any failure of that insertion (validation, store write, or notification pipeline) under the message 'cannot create card'. The card is not created when this is returned.

Source

Thrown at server/app/cards.go:29

)

func (a *App) CreateCard(card *model.Card, boardID string, userID string, disableNotify bool) (*model.Card, error) {
	// Convert the card struct to a block and insert the block.
	now := utils.GetMillis()

	card.ID = utils.NewID(utils.IDTypeCard)
	card.BoardID = boardID
	card.CreatedBy = userID
	card.ModifiedBy = userID
	card.CreateAt = now
	card.UpdateAt = now
	card.DeleteAt = 0

	block := model.Card2Block(card)

	newBlocks, err := a.InsertBlocksAndNotify([]*model.Block{block}, userID, disableNotify)
	if err != nil {
		return nil, fmt.Errorf("cannot create card: %w", err)
	}

	newCard, err := model.Block2Card(newBlocks[0])
	if err != nil {
		return nil, err
	}

	return newCard, nil
}

func (a *App) GetCardsForBoard(boardID string, page int, perPage int) ([]*model.Card, error) {
	opts := model.QueryBlocksOptions{
		BoardID:   boardID,
		BlockType: model.TypeCard,
		Page:      page,
		PerPage:   perPage,
	}

View on GitHub (pinned to a84bbb65e3)

Solutions

1. Inspect the wrapped cause from errors.Unwrap — fix the underlying validation or store error it names.
2. Validate the card (Title, BoardID/ParentID set, valid types) before calling CreateCard.
3. Confirm the target board exists and the user has permission to add blocks to it.
4. Check plugin/websocket notification hooks for panics or rejections if validation and store are fine.

func validateCard(c *model.Card) error {
    if c == nil {
        return errors.New("card is nil")
    }
    if strings.TrimSpace(c.Title) == "" {
        return errors.New("card title is required")
    }
    if c.BoardID == "" {
        return errors.New("card BoardID is required")
    }
    return nil
}
// call validateCard(card) before app.CreateCard

func isValidCard(c *model.Card) bool {
    return c != nil && strings.TrimSpace(c.Title) != "" && c.BoardID != ""
}

card, err := app.CreateCard(card, userID, false)
if err != nil {
    if strings.Contains(err.Error(), "cannot create card") {
        return fmt.Errorf("card creation rejected: %w", errors.Unwrap(err))
    }
    return err
}

When it happens

Trigger: App.CreateCard failing inside InsertBlocksAndNotify: invalid card fields (empty title/boardID, bad parentID), block validation failure, store insert error, or an error thrown by the block-change notification hook (websocket/plugin subscribers).

Common situations: API clients posting cards missing required fields; database outages; a plugin's WatchBlockChange hook rejecting the insert; board ID pointing to a deleted board.

Related errors

• Block2Card fail: %w
• no user ID
• No User IDs
• block fields size limit exceeded
• at least one board is required

AI-assisted analysis of mattermost-community/focalboard@a84bbb65e3 (2026-08-30). Data as JSON: /api/errors/767456050d539471. Report an issue: GitHub.