Error

[Light-YT]

Make sure your device is connected in DFU mode
Checking theiphonewiki for 13.3 keys...
Found Keys!
Downloading 13.3's BuildManifest.plist
Extracting: BuildManifest.plist, from iPhone_4.0_64bit_13.3_17C54_Restore.ipsw
Getting SHSH for signing images
ERROR: Failed to save shsh

[deev3e]

Maybe today the issue is related to different problems than it was year ago, but anyway I wanted to share observations:

Today I noticed this issue, and found out it is related to resources/bin/tsschecker. This app now fails with making checks for iOS 15 (something changed in requests with the newest system release). tsschecker is called from resources/img4.py. So to make it resolve probably you can open /resources/img4.py, search for line:

so = subprocess.Popen(f"./resources/bin/tsschecker -d {tssmodel} -e 85888280a402e -l -s", stdout=subprocess.PIPE, shell=True)

and replace it with:

so = subprocess.Popen(f"./resources/bin/tsschecker -d {tssmodel} -e 85888280a402e -i 14.8 -s", stdout=subprocess.PIPE, shell=True)

tsschecker -l parameter stands for "latest (system version)". We can change it with lower version -i 14.8