childModule for errorCallback

childModule.html

<template>
    <c-grand-child></c-grand-child>
</template>

childModule.js

import { LightningElement,track } from 'lwc';
import agGridcommunity from '@salesforce/resourceUrl/agGridcommunity';
export default class ChildModule extends LightningElement {
  renderedCallback(){
    Promise.all([
        loadStyle(this, agGridcommunity + "/agGridCommunity/ag-grid.css"),
        loadStyle(this, agGridcommunity + "/agGridCommunity/ag-theme-alpine.css"),
        loadScript(this, agGridcommunity + '/agGridCommunity/ag-grid-community.js')            
    ])
        .then(() => {
            console.error('isCSSLoaded');
        })
        .catch(error => {
            this.dispatchEvent(
                new ShowToastEvent({
                    title: error.message,
                    message: error.message,
                    variant: 'error'
                })
            );
        });
}
}

@dhaniksahni Thanks for sharing. Were you able to load AgGrid inside LWC? It is not related to error handling. We want to use AgGrid in LWC; however, it is not supported because of locker service.