When I tried to upgrade my phone 3GS 3.x to a 4.x firmware found on osxdaily.com, I got the famous “this device isn’t eligible for the requested build”.
My jailbroken device was on a 3.1.3 firmware with Cydia installed. After trying different 4.x firmwares, I googled this error message and found an interesting thread here.
I followed their advice and it worked:
- Install TinyUmbrella,
- Clicked on my device,
- went to Advanced tab and unchecked “Request SHSH from Cydia”,
- Started TSS Server,
- Entered Recovery,
- and finally in iTunes clicked on Restore (with option key) and selected a 4.1 firmware,