Hi.
I understand your frustration. From my experience, Stencyl 3.4 doesn't work with xcode 9.2 and I had to downgrade xcode to get simulators to work.
I managed to downgrade mine following the instructions here:
https://stackoverflow.com/questions/31011062/how-to-completely-uninstall-xcode-and-clear-all-settingsBasically, I uninstalled XCODE, and then to clean up all the remaining XCODE files, I copy/pasted this line in the terminal program:
rm -rf /Applications/Xcode.app /Library/Preferences/com.apple.dt.Xcode.plist ~/Library/Preferences/com.apple.dt.Xcode.plist ~/Library/Caches/com.apple.dt.Xcode ~/Library/Application Support/Xcode ~/Library/Developer ~/Library/Developer/Xcode ~/Library/Developer/CoreSimulatorAfter that, I downloaded an older version of XCODE (8.3.2) from the Apple Developer website:
https://developer.apple.com/download/more/8.3.2 Supports up to IOS 10.3.
I am unsure what the maximum version of xcode can be supported by stencyl 3.4.
I hope this helps.