Loading aborted due to error reloading workflow data

[comfy-pr-bot]

Custom Node Testing

• I have tried disabling custom nodes and the issue persists (see how to disable custom nodes if you need help)

Your question

Loading aborted due to error reloading workflow data
TypeError: this.widgets.values().filter is not a function

All worked fine yesterday. No changes or updates. Then today, fails on launch or if any workflow is loaded. Searched, others had same issue in last two years, but no fix found.

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No response

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This issue is transferred from: comfyanonymous/ComfyUI#10826

Original issue was created by @FilipeF12 at 2025-11-21T20:16:24.000Z

┆Issue is synchronized with this Notion page by Unito

[dosubot]

This error is caused by a recent frontend code change: the code now calls .values().filter(...) on this.widgets, but this.widgets is an array, and .values() returns an iterator, not an array—so .filter isn't available, resulting in the TypeError. This was introduced in a recent refactor and widget feature update (PR #6661, PR #6752), merged just before the issue appeared.

The fix is to replace this.widgets.values().filter(...) with this.widgets.filter(...) in the codebase. Until this is patched, the error will persist whenever workflows are loaded, regardless of custom node status. This is a frontend regression, not a custom node or environment issue.

To reply, just mention @dosu.

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[FilipeF12]

@dosu can you be more specific about which files need editing to make the changes?

[christian-byrne]

@FilipeF12 Do you happen to have a workflow that triggers this?

[AustinMroz]

And what browser are you running? Iterator.filter() lists support for all browsers. Is it possible your browser hasn't been updated in ~2 years?

[FilipeF12]

@christain-byrne - moot now

@AustinMroz FF 128.6.0esr

UPDATE: updated FF to 140.5.0esr and all is good. A few non-fatal issues seem resolved now as well.

Christian, Alex and Austin: a big thank you!