Is it possible to download iOS 7.1 Simulator on Xcode 6.4 on El Capitan, I see strange error:
Could not download and install iOS 7.1 Simulator. The request timed out. Network Diagnostics can help you solve network connection problems.
No. The iOS 7.1 Simulator runtime is not supported on OS X El Capitan. It should not even be presented as an option.