Generally this is a good error message but in this specific case the grid is doing some javascript magic and is trapping keyboard events and handling the tabbing directly instead of allowing the browser to do it. So you can't actually tab to either of the two <div>
elements it's complaining about:
<div class="ag-tab-guard ag-tab-guard-top" role="presentation" tabindex="0"></div>
...
<div class="ag-tab-guard ag-tab-guard-bottom" role="presentation" tabindex="0"></div>
The scanning tool doesn't know anything about the javascript behind the scenes so it doesn't know this and will flag it as an issue.
You can see this a little more clearly on the grid column headers, which are keyboard focusable and have a role="columnheader"
but they also have tabindex="-1"
, meaning you should not be able to tab to them directly but can move the focus to them programmatically (from javascript).
<div role="columnheader" tabindex="-1" aria-sort="none" aria-description="Press ENTER to sort. Press CTRL ENTER to open column menu." aria-colindex="4">
So the only way the column headers can receive focus is if the javascript is trapping on the tab event and programmatically moving the focus there.
If you're trying to have a clean ARC scan, unless you can modify the grid code or are allowed to customize your ARC scan to filter out these two elements, you'll have to live with this error that isn't really an error.