I just upgraded my Xcode to beta (8.0) and I lost the previous iOS8 sim that I had in the previous version. I still need iOS 7 SDK and iOS 8. Help any help
No. The running time of the iOS 7.1 simulator is not supported on macOS 10.11 or later. Xcode 8 requires macOS 10.11 or later. Therefore, they are incompatible based on host OS requirements.
No, this is not a way to install iOS7 in Xcode 8, because they differ in runtime.