Get blank page and js error "this.manager.logValidationError" is not a function when spfx registered

Just in the last few hours my site has started loading up document libraries as blank (just a ribbon header).

In the JS console is an error

Uncaught TypeError: "this.manager.logValidationError" is not a function

It seems this is being caused because when you register spfx some code is injected that executes 

https://res-1.cdn.office.net:443/files/sp-client/listview-host-assembly_en-us_ec982ae4e67a37a7a939bd897f289600.js%22

and this file sets window.ODSP_TELEMETRY_MANAGER to an object that is missing the "logValidationError" function.  Actually it doesn't *always* happen, it depends on the order that the js scripts load, but more often that not.  For a site with no spfx registered there's no issue.

Is this a known issue, and if not, what can I do about it?

Thanks

Dylan