When I launched Cydia for the first time, it took some time “Preparing Filesystem” and it resprung the device as expected. But when I launched Cydia, I kept getting “Failed to fetch http://apt.saurik.com/dists/ios/1240.10/main/binary-iphoneos-arm/Packages.bz2 Hash Sum mismatch” error.
Due to this error, Cydia wasn’t able to load all the repos and the packages, making it impossible to install new jailbreak tweaks, which kind of makes jailbreaking your device pointless.
I tried several solutions such as killing Cydia and relaunching it, rebooting my iPhone, using the volume up trick while rebooting, but it did not seem to help. I kept getting the “failed to fetch” error. Tapping on Refresh also resulted in the same error. I didn’t want to restore my device and jailbreak my devices again as it too time-consuming.
How to fix “failed to fetch” error in Cydia
I found a strange solution to fix the error. To fix the error, I had to disable Wi-Fi. You can either use your iPhone’s cellular connection or connect your device to your iPhone’s Hotspot.
When I tapped on Refresh in the Sources tab after disabling Wi-Fi I got the “failed to fetch” error again. But this time I didn’t get “Hash Sum mismatch”. I didn’t face this issue on my iPhone 5s.
Tapping on Refresh in the Sources tab again resolved the issue. I got Reloading Data, and was able to install new jailbreak tweaks using Cydia.
I haven’t faced this issue before. But disabling Wi-Fi worked on my iPhone 6s and iPhone 5s.
So I thought of sharing it as I hit it on both the devices. I hope it saves you the trouble of restoring your device. Let me know if you faced this issue, and if this solution helps resolve it.