Failed to execute 'attachShadow'

[dimaqq]

Failed with:
Failed to execute 'attachShadow' on 'Element': Shadow root cannot be created on a host which already hosts a shadow tree.

Source: chrome-extension://gfhlfpnpjokocfohicmfbgjneiipfeil/scripts/pageScript.js in HTMLElement.connectedCallback at line 112:1910

Chrome version:93.0.4577

[dimaqq]

The stack trace is weird, it seems that that happens when user code calls this.appendChild( elem ); in random jQuery

[azu]

Fmm, Can you provide a website for reproducing?

Shadow root cannot be created on a host which already hosts a shadow tree.

That web site may have used Web Component.

[dimaqq]

No, sorry... The website is oldschool (jQuery), it wouldn't know about web components.
This came from automated reporting from customer system.
If someone manages to reproduce this, I'll update here.
Also, I can't be sure about other extensions that user's browser may have had installed.