All Vendor management options have disappeared

After an email from one of our vendors about not receiving email notifications when products sell, we have found that all of our vendor options/settings appear to have disappeared from the WCFM settings pane.

All worked perfectly until 48 hours ago. Checking logs etc, I can see no updates that have been applied to the WP base, theme or any other plugins on the site. Is anyone able to advise what might be causing the issue?

All products remain live and continue to sell as normal – just that products are no longer showing the ‘Vendor’ information etc and our vendors have no access. Any associated settings on the WCFM settings panel have also vanished.

It may not have anything to do with the issue – but the icon for WCFM in the WP ribbon (I mean the menu at the top of the page when logged in as an admin) have also changed to an image that looks like the original image might have disappeared.

Thanks in advance.