This is because @angular/flex-layout doesn't support Angular's Renderer2 yet, which is the only supported version in Angular 5.0.0-beta.5. Prior to that release, Renderer could be used as well and flex-layout takes advantage of that service in NgClass extensions.

I've opened the original issue over at @angular/angular right HERE
Also, it seems this will likely be fixed with https://github.com/angular/flex-layout/pull/391 which is pending right now.
@angular/flex-layout has a ClassDirective to support responsive APIs for class and ngClass.
This directive no longer extends the ngClass fro @angular/core. Instead it internally composes an instances of this class (if needed) and delegates actions to that instance.
With @mhevery's help, the Flex-Layout now uses a Renderer2.
Any idea when this fix will be committed?
The PR(s) are in the queue and should be merged into master today. We hope to publish Beta.10 soon.
Great, thanks....this one bit me
Dang cost me 2 days to figure out where it came from.. the old fashioned remove one component/module at a time until I was down to Angular/Flex :)
Looking forward to the update, guys :) thanks
The renaming and breaking change of renderer -> renderer2 occurred back in Angular 4.0 rc.1:
Hi guys, any news about this?
It doesn't appear to have been merged into master yet... nobody is able to upgrade to Angular 5 beta 5 or beta 6...
Thanks for your great work, really hoping for this to be merged soon.
@spock123 - hopefully this will be merged today.
This issue has been automatically locked due to inactivity.
Please file a new issue if you are encountering a similar or related problem.
Read more about our automatic conversation locking policy.
_This action has been performed automatically by a bot._