Note to Windows Users: You can perform these same steps with an ssh app like putty on Windows.
Make sure your jailbreak is enabled by launching the Cydia app. If it opens and closes right away launch mach_portal from your SpringBoard to re-enable the jailbreak.
Make sure your iPhone is connected to the same wireless network as your computer.
Launch Terminal from the Applications:Utilities folder on your Mac.
SSH to your iPhone using the following command:
Replace 'your.ip.address' with the IP address of your iPhone. If you don't know how to find that, please see our tutorial on "How to Find the IP Address of Your iPhone".
If this is the first time you are doing this, you may be asked to confirm you want to continue. Type 'yes'.
Enter your iPhone's root password when prompted. Please note, if you have just jailbroken then this will be 'alpine'. Hint: You should really change that using the command 'passwd' once logged in.
Enter the following command into the Terminal window:
chmod 777 /var; chmod 777 /var/mobile; chmod 777 /var/mobile/Library; chmod 777 /var/mobile/Library/Preferences
***Although, Luca Todesca offered chmod 777 as the fix, you may want to try 755 first as 777 gives read, write, and execute permissions to owner, group, and others.
Reboot your iPhone and enjoy LTE!
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