Desinger Extension Issues on Live Editing Beta Feature

Developers
1

Hi there,

it looks like the live editing feature you’re currently rolling out is breaking our Webflow App extension. Currently our users that have been included in the beta rollout already get this error:

index-ByLpi4gV.js:14 Error: Missing element {“component”:“692eea2c488065958e026a28”,“element”:“55a18f20-fee7-e376-ac04-19ca065d1107”}.
at throwElementMissingError (entrypoint-designer-extensions-client.4b205f816a7eaa07.js:256:712065)
at Object.Error (entrypoint-designer-extensions-client.4b205f816a7eaa07.js:256:711287)
at Type_when (entrypoint-designer-extensions-client.4b205f816a7eaa07.js:184:112033)
at Object.append (entrypoint-designer-extensions-client.4b205f816a7eaa07.js:256:710951)
at async ot.addNode (index-ByLpi4gV.js:31:247694)
at async Promise.all (http://64ede53a7f310eeba7cfb03e.webflow-ext.com/690c70b36d8292dd945b0c57/index)
at async ot.addNodes (index-ByLpi4gV.js:31:245884)
at async Object.N [as createMap] (index-ByLpi4gV.js:373:2108)
at async v (BuildInView-CGhxvCWR.js:1:11518)

Why is it no longer possible via the Designer Extension to insert more items into the cms-collection-list (dynamic list) element before a CMS collection has been selected?

Is there now any way to select the CMS collection via the Designer API (to work around this error)?

Best

Lucas

1 Like
2

Quick update – we investigated the issue a bit deeper.

Test setup

  1. Select the Collection Item

    Screenshot 2025-12-05 123608
    Screenshot 2025-12-05 123608229×121 4.5 KB

  2. Run the following code in the extension:

let DynamoItem = await webflow.getSelectedElement();
let newChild = await DynamoItem.append(webflow.elementPresets.DOM);
console.log(newChild);

The call resolves successfully and returns a valid element:

{
  "id": {
    "component": "6931a1ba4d7f1125d6363f17",
    "element": "886f3ee7-701c-f6f6-5e26-ae9f9a1be539"
  }
}

Observed behavior

At the same time, without any visible error in the console or on the code side, this happens:

Screenshot 2025-12-05 124058
Screenshot 2025-12-05 1240581050×538 50.8 KB

Also, the DOM element is not actually placed inside the Collection Item in the Designer.

So from the API side everything looks successful, but the element is neither visible in the DOM tree nor in the canvas.

Follow-up: using the returned element

If we later try to use the returned newChild reference, we get an “element missing” error (as if the element never really existed in the DOM), even though the initial append call resolved without error

Hope that helps you reproduce the issue.

Cheers,
Lucas

3

Thanks @luci for these detailed errors and repro steps! While realtime is not rolled out 100% yet to all customers, we’re continually prioritizing to look at these types of issues. I’ll be sure to raise this with our team to see whats up, and report back if we need more details. Thank you again!

2 Likes