Thanks for A's plan @dazboj Solved: iOS 27.2 Runtime Shows Ready but Is Missing in Device Hub I found the root cause on my Mac: my login account had accidentally been added to the daemon group. The Cryptex runtime directory permissions were: drwx---r-x root daemon /private/var/run/com.apple.security.cryptexdIn Unix permissions, if a user belongs to the directory’s group, macOS applies the group permissions before the “other” permissions. Since the daemon group has ---, my account could not access the Cryptex-mounted Simulator Runtime files. This produced a confusing state: xcrun simctl runtime list -v showed iOS 27.2 as State: Ready iOS 27.2 showed Mounted: NO xcrun simctl list runtimes did not list iOS 27.2 Device Hub had no usable iOS 27.2 runtime Creating a simulator failed with Invalid runtime Check whether your account belongs to the daemon group: idor: dscl . -read /Groups/daemon GroupMembershipIf your login username appears in the daemon group, remove it: sudo dseditgroup -o edit -d <your_username> -t user daemonFor example: sudo dseditgroup -o edit -d tikbai -t user daemonThen reboot the Mac. After reboot, verify that daemon is no longer listed: id -Gn | tr ' ' '\n' | grep -x daemonThis command should return no output. Finally, verify the runtimes: xcrun simctl list runtimesAfter removing my account from daemon and rebooting, iOS 27.1 and iOS 27.2 runtimes became available again and Device Hub could use them normally. No manual deletion of /System/Library/AssetsV2 or runtime re-download was required.