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Breaking on exceptions
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To instruct the debugger to pause on an `exception <https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error>`_, tick these checkboxes in the :ref:`Breakpoints list <debugger-ui-tour-breakpoints-list>`:
- Pause on exceptions
- Pause on caught exceptions
.. image:: version64ui.png
:alt: Screen shot showing "Pause on exceptions
:class: center
When an exception occurs, the line where it occurs is highlighted in the source pane, with a squiggly red line under the problematic code. A tooltip describes the exception. Starting in Firefox 80, a disclosure triangle within the tooltip reveals a stack trace.
.. image:: exception-tooltip-stacktrace.png
:alt: Screenshot of a tooltip for an exception
:class: center