Office fabric ui core style stopped working

[premiimt20]

Hi Team,

Today randomally All UI broke down from out SPfx webparts. We have used office fabric ui, with no javascript framework.
there used to be class name ms-SPLegacyFabricBlock earlier but no it is missing from div. we have not uploaded new package since Oct 2020.

Thanks
Prem Dubey

[pavan2920]

:global{
@import 'node_modules/office-ui-fabric-react/dist/css/fabric.css';
}

You can try this pointing to the local folder instead of CDN. Works for me.

[jnimmala]

try adding fabric.css ref to project scss file
@import '~office-ui-fabric-react/dist/css/fabric.css';

SharePoint/sp-dev-docs#5763

[pavan2920]

@jnimmala I had this file in scss file itself but it stopped working today so used above work around.

[westleyMS]

The product team has turned off a feature that may have contributed to this.

[westleyMS]

Just to make clear here that the feature is working again, and its failure was not intentional. You do have to add the property to SPFx 1.8.2 or later webparts in the manifest per this article-
Safely use legacy Office UI Fabric Styles (after SPFx v1.8.2)

Here is the important part-

Ensure that the webpart manifest demands legacy Fabric core styles be loaded onto the page. This is done by specifying loadLegacyFabricCss: true in the solution manifest.

This is expected to consistently work going forward. This outage was not intentional.