There is no issue in Design view related to this. mate_08_9.swc is not compatable with the sdk you are using. So no change planned from FB side for this. Please contact the swc owners to resolve the issue.
Theoritically this should not affect the DV fucntionalities (which dont depend on this swc)
Very soon we will be providing an applicaiton (Not part of FB) which can be used by the swc owners to anlyse the DV reported issues of their swc.
thank you for your answer.
Sorry for my late response. I understand this. In the forum of mate, they are link to the bugbase and say, this is a bug in fb.
But i trust adobe :-)
Is there a way to supress these warnings?
I just want to say that this is the case with Parsley as well. I've recompiled Parsley using the same SDK (22.214.171.12486) as my current project and that doesn't resolve this issue. And for me I cannot use the Design View at all, it's just all grey.
I've had this issue before with the initial Flash Builder 4 release and now starting to use Flash Builder Burrito it's back again.