Which Flash exactly you will install? ActiveX or/and Plugin? ActiveX only up to W7, in W8 and higher Flash Player comes through Windows Update/WSUS.
I think the failed is on W8 Clients. If yes, you have to create a new Rule, LowerW8Clients.
I think the failed is on W8 Clients. If yes, you have to create a new Rule, LowerW8Clients.