I can tell you guys that this issue is only related to all Xcode versions from 16.0 to 16.2 !! I downloaded Xcode 15.4 and managed to run it and i can download runtimes no problem !

Here is what happen with Xcode 16.0 to 16.2 ! Hope you can fix the issues soon :(

Other people are having same issue ! https://developer.apple.com/forums/thread/771499

same problem as well i created a post here : https://developer.apple.com/forums/thread/774890?login=true&page=1#829374022

The issue is still happening with Xcode 16.4 as well i cannot install iOS 18.4+ !!!! Its weird that Apple did not adresse this issue so far !!!

Just updated to Xcode 26.0.1 same issue still here !!! Im on macOS : 15.7.1 !!! cannot believe it dude.

Well iOS 18.0+ cannot be installed from xcode !! this is xcode 26.0.1. Only till iOS 17.5 as you can clearly see ! The only way to install iOS 18.2 so far i can find on Apple servers is by doing so manually and downloading the dmg her e: https://developer.apple.com/download/all/?q=ios

i finally fixed it guys. And here is what i did in case this helps someone !!!! in /etc/hosts : Make sure no *.apple.com has the 0.0.0.0 !!! On System prefs : in this state "Apple intelligence is not working yet probably, stuck at 100% or going from 0 to 100 in 1 sec" Disable Apple inteligence Switch Region to United States (I was in region France) Enable Siri and set language to English United States (French doesn't work with Apple Intelligence) i sign-out form apple account and logged back in after the restart ! Restart macOS Enable Apple Inteliggence -- Here you will see that the download started and progress now works perfectly Wait untill download end and everything is all perfect !! (Don't ruch take time) On Xcode : Now everything will work perfectly !!! Tested on Xcode 16.4 & 26.0.1