I am experiencing this today.. current free space on Disk is 67.98GB.. if Apple is requiring you to maintain anywhere close to this amount of space in order to install an iOS Simulator platform.. that is ridiculous! I have tried both installing the iOS_17.2_Simulator_Runtime.dmg manually by downloading from Apple as well as via the GUI -> Settings -> Platforms.. Error I am getting: Minion-Carl ~ % xcrun simctl runtime add ~/Downloads/iOS_17.2_Simulator_Runtime.dmg An error was encountered processing the command (domain=com.apple.CoreSimulator.simdiskimaged.SimDiskImageError, code=14): Cannot copy the image because the disk is almost full I have spent way too much time trying to resolve getting an iOS simulator env onto my development machine.. After 7 years developing for iOS I am really disappointed. Follow Up What ultimately worked for me was the solution provided above re: Mac OS X Settings -> Storage -> Developer.. clear out unneeded (Hopefully) platform files followed up with a Restart of the machine. I was then able to use the downloaded .dmg file and install via terminal. Keep in mind that I did have ~60GB of free storage space prior to that so perhaps it's something to do with application sandboxing of storage on the Mac (simply guessing here?) .. Good luck!