a '{event}' before-handler threw; the action was cancelled.

Warnings reference › kanban:beforeThrow:*

Identifier

kanban:beforeThrow:*

Raised by

Kanban

Since

1.36.0

What happened

A before… handler on the board threw. A before-handler decides whether the action happens, so a throw is treated as a veto and the move, add or edit was cancelled. It is reported rather than swallowed because a cancel nobody asked for is indistinguishable from a broken board.

The fix

The error is attached to the console line. Return false to veto deliberately; fix the handler if the throw was not intended.

The smallest fix

board.on('beforeMove', ({ to }) => allowed(to));

Reference

Covered in full at the API reference.