Error 20 Help Needed

[engelke2010]

I am trying to downgrade my iPhone 4 from 4.3.5 to 4.3.3. I do have my SHSHs saved. Every time I try to downgrade, I get the error 20. I have my Windows Firewall and Norton Firewall & Antivirus disabled and the last two lines of my Hosts file are:

#74.208.10.249 gs.apple.com
127.0.0.1 gs.apple.com

Why can't I downgrade? Why do I keep getting the stupid error 20? Please help!

[i.Annie]

You have the TSS server in TinyUmbrella running?

[engelke2010]

Yep. I even re-downloaded the firmware

[Mes]

4.3.3 and 4.3.5 ip4 BB's are the same so a normal restore w/SHSH blobs should work. But since it doesn't, try this: Clean/erase ALL gs.apple.com lines from hosts. Reboot computer. Start TU + TSS server. Verify no TSS error. Build a Snowbreeze cfw 4.3.3, expert mode, no activation (if AT&T), enter pwnd-DFU w/Snowbreeze, shift/click restore cfw w/iTunes. If iTunes error 10xx, enter ...normal DFU .. and run fixrecovery43.

[Mysterion]

I am getting the same Error 20 while trying to downgrade my Verizon iPhone 4 from 4.2.9 to 4.2.8. I'm stuck on Connect To iTunes logo screen now. I have the 4.2.8 shsh blobs. I followed all the steps on iPhoneBlogr.com and got Error 20 in the end. Any fix?

[i.Annie]

If all else fails I would suggest a custom 4.3.3 fw. Just run the TSS server, set device into pwned dfu with sn0wbreeze/redsn0w/pwnagetool (doesn't matter which one really) then open iTunes and restore to cFW

[engelke2010]

Thanks for everyone's help. I will try this today when I get home from work. I never built a Custom Firmware as I thought it was Mac only. I'm glad I was wrong.

[i.Annie]

Pwnagetool is a Mac only tool and Sm0wbreeze is Windows only. They both create custom firmwares.

[engelke2010]

Thank you again everyone for your help. I am very happy (and very relieved) to say it worked and I am now re-jailbreaking on 4.3.3. I had some stupid problems along the way, but all is fine now.

[Mes]

Congratulations. Live and learn, that's the way of things Soon, you'll be the expert !

[i.Annie]

cFW FTW glad it worked!

[spd09]

I have a iphone4 neverlocked, trying to downgrade from 4.3.5 to 4.3.3 in order to jailbreak. I dont care about the baseband, just wanna get to 1015 error. but nothing i've tried so far has worked. still getting error 20 and error 3194. (i don't have SHSH blobs, as i purchased the iphone secondhand, and it came with 4.3.5)
Tried so far:
The simple method no changes.
with tinnyumbrella openned and tts server started.
jailbroken with redsnow, the tried to resstore 4.3.3
made custom ipsw with sn0wbreeze
changes to hosts file.

So... if anyone has an better idea, please HELP!!!

[i.Annie]

If you don't have SHSHs for 4.3.3 you cannot downgrade to it.