-1004 Three conditions of jailbreak failure
此问题为电脑导致，请更换一台电脑进行越狱操作。卡在 40%，首先检查 pc 和设备上有无后台程序抢占 cpu 资源，pc上通过任务管理器观察一下即可，设备可以通过重启确认；其次连接设备的 usb 线和 pc 上的 usb 口也是影响因数之一，请尝试换个 usb 口接入和 usb 数据线。
It was caused by computer. Please try on another computer. If jailbreak is stuck at 40%, firstly check whether background programs are preempting CPU resources by observing task manager on the computer. You can reboot the device to confirm. Secondly, change USB on the computer and USB cable connecting iDevice and the computer.