How to Fix iTunes error 1015 after firmware upgrade on iPhone?

[system232]

Can you try to download RecBoot 1.0.2 that could solve the issue for you hopefully:

1. Download RecBoot 1.0.2
2. Run "RecBoot Exit Only"
3. Click the "Exit Recovery Mode" button
4. The screen on the iPhone will go black. At this point, UNPLUG the iPhone. (before it starts back up)
5. It will boot up correctly after finishing the firmware install.
6. Now plug your iPhone back in and complete a normal restore.

Thanks Solomon,
I changed the computer and I was able to get into DFU and run Ifaith to download shsh for 4.3.3. Now I have another problem, I tried to load the built firmware I did with the ifaith shsh file but it will not restore.
After the shsh were donwloaded I did normal restore from Itunes and it is now at 4.3.5. Even if I try to use the custom firmware I did with Ifaith again I get error 21.
Please help

[Ashert]

Thanks Solomon,
I changed the computer and I was able to get into DFU and run Ifaith to download shsh for 4.3.3. Now I have another problem, I tried to load the built firmware I did with the ifaith shsh file but it will not restore.
After the shsh were donwloaded I did normal restore from Itunes and it is now at 4.3.5. Even if I try to use the custom firmware I did with Ifaith again I get error 21.

If you want to fix iTunes error 21 then you must put your iphone into DFU mode using the following instructions:

1. Connect your iphone to your PC via USB cable and launch iTunes.
2. Hold down the Home+Power button for 10 seconds.
3. After 10 seconds, release the Power button but keep holding the Home button until iTunes detect your iPhone in recovery mode.
4. Once your iDevice is in DFU mode, you should see nothing on its screen. It should be completely blank.
5. After that restore custom IPSW and hopefully this time you will not get iTunes Error 21.

[system232]

If you want to fix iTunes error 21 then you must put your iphone into DFU mode using the following instructions:

1. Connect your iphone to your PC via USB cable and launch iTunes.
2. Hold down the Home+Power button for 10 seconds.
3. After 10 seconds, release the Power button but keep holding the Home button until iTunes detect your iPhone in recovery mode.
4. Once your iDevice is in DFU mode, you should see nothing on its screen. It should be completely blank.
5. After that restore custom IPSW and hopefully this time you will not get iTunes Error 21.

Thanks Ashert for the info, but the trouble is I am getting this error after I put the phone in DFU mode and start the restore with Itunes and the custome ISPW.

[Namchan]

Probably the error gets solved in DFU mode itself but as you said you started getting this error after DFU, i think you should go through the following discussion that is with same error code and its solutions:
How do i fix error 1015 on iphone 3g 4.2.1
Error 1015-iphone
iTunes error code from 1 & 1015

[system232]

Probably the error gets solved in DFU mode itself but as you said you started getting this error after DFU, i think you should go through the following discussion that is with same error code and its solutions:
How do i fix error 1015 on iphone 3g 4.2.1
Error 1015-iphone
iTunes error code from 1 & 1015

I am trying to downgrade my phone so I can do untethered JB. I saved SHSH with Ifaith before I upgraded to 4.3.5 as they were not available with TU. The reason why I restored to 4.3.5 was because I had issues with the phone. Now I am trying to restore with the signed ISPW copy I did with the IFaith shsh. However, when I try to restore the phone start to restore than I get the error 21. If there is any other way to downgrade I can try.
Thanks a lot for all the help

[Simond]

Can you try to turn the phone off, unplug it from the computer, hold down the home button and continue to hold it down while plugging the phone back into the computer. Wait until you get the "connect to itunes" message and try again with the jailbroke ipsw and see if that works for you or not. Normally, error 21 or error 1601 means there is something wrong with your USB connection or with the communication between iTunes and the iPhone.

[system232]

Can you try to turn the phone off, unplug it from the computer, hold down the home button and continue to hold it down while plugging the phone back into the computer. Wait until you get the "connect to itunes" message and try again with the jailbroke ipsw and see if that works for you or not. Normally, error 21 or error 1601 means there is something wrong with your USB connection or with the communication between iTunes and the iPhone.

Thanks Simond, I tried your instruction but now I am getting error 20 instead of 21. I bought new USB cable but there is no change this is weird I am not sure what else to try. Any more help is much apreciated.

[HankH]

Error 20, 21 and etc are These errors usually take place at what time security software interferes through the restore and update method. To resolve this you have to confirm that the problem is a third-party security software problem. And after that you have to update your security software. Subsequent to updating your security software, organize it appropriately to permit iTunes on the way to contact Apple. If the up to date obtainable version of your security software is mismatched through iTunes, you are able to disable the security software and examine if it is the basis of the problem. If you want the more information about this then I will suggest you to visit the apple support site there you will get appropriate solution over there.

[system232]

Error 20, 21 and etc are These errors usually take place at what time security software interferes through the restore and update method. To resolve this you have to confirm that the problem is a third-party security software problem. And after that you have to update your security software. Subsequent to updating your security software, organize it appropriately to permit iTunes on the way to contact Apple. If the up to date obtainable version of your security software is mismatched through iTunes, you are able to disable the security software and examine if it is the basis of the problem. If you want the more information about this then I will suggest you to visit the apple support site there you will get appropriate solution over there.

I tried different computer and still getting the same error. I tried to downgrade with shsh files to 4.1 I got error 20. No matter what I do I either get error 21 with custom ipsw or error 20 if I do restore with start shsh with tiny umbrella. Please help, I am starting to think there is maybe a problem with this phone.

Thanks in advance for the help

[Pugsly]

I tried different computer and still getting the same error. I tried to downgrade with shsh files to 4.1 I got error 20. No matter what I do I either get error 21 with custom ipsw or error 20 if I do restore with start shsh with tiny umbrella. Please help, I am starting to think there is maybe a problem with this phone.

It seems to be an internal issue with the iphone itself so it will be better to take it to the service center and see if there are som possibilities to fix this issue. As you have already tried all the methods, it surely seems to be an iphone issue itself. If you still persist to do a manual troubleshoot then it could brick totally and wont be useful again.

[system232]

It seems to be an internal issue with the iphone itself so it will be better to take it to the service center and see if there are som possibilities to fix this issue. As you have already tried all the methods, it surely seems to be an iphone issue itself. If you still persist to do a manual troubleshoot then it could brick totally and wont be useful again.

Thanks for the info.
Just want to add that the only thing would work on this phone is just normal restore 4.3.5.
I tried downgrading my 3g from 4.2.1 to 4.1 with shsh file and tiny unmbrella worked fine, this makes me believe there is something wrong with that phone but what is it I don't know. The only catch is what would I tell Apple if I take it back to them, if the normal restore works they wouldn't care and they wouldn't fix it for me. I still have couple of weeks warranty but I must give them a good reason for why I need to replace/repair it.
Any suggestion is very much appreciated.

[Brooks]

Error 20, 21, 34, 37 errors typically occur when security software interferes with the restore and update process. Verify your computer has the correct date, time, and timezone. Verify you are logged in as an administrative user. Verify the latest version of iTunes is installed. Verify the latest Windows updates are installed. Verify your router or modem firmware is up-to-date. Also, disable any firewall or antivirus software from your pc and then test again.

[system232]

Error 20, 21, 34, 37 errors typically occur when security software interferes with the restore and update process. Verify your computer has the correct date, time, and timezone. Verify you are logged in as an administrative user. Verify the latest version of iTunes is installed. Verify the latest Windows updates are installed. Verify your router or modem firmware is up-to-date. Also, disable any firewall or antivirus software from your pc and then test again.

error 20 occurs only if I try downgrade using shsh with tiny umbrella on my 3gs, what interesting was it didn't happen with my 3g using same process. so why all these security isuues are not a problem with 3g if this is the cause of the error. However, I did do all of the above except my router and firmware latest update not sure if it is apllicable to mine.

Thanks

[Brooks]

error 20 occurs only if I try downgrade using shsh with tiny umbrella on my 3gs, what interesting was it didn't happen with my 3g using same process. so why all these security isuues are not a problem with 3g if this is the cause of the error. However, I did do all of the above except my router and firmware latest update not sure if it is apllicable to mine.

Change the Hosts file and see if that makes any difference. Hosts should be in your /etc folder. If not just create one (text format) with the following contents:

#########

127.0.0.1 localhost
255.255.255.255 broadcasthost
::1 localhost
fe80::1%lo0 localhost


### ipod/iphone ###
# 74.208.105.171 gs.apple.com
74.208.10.249 gs.apple.com
# 74.208.*.* gs.apple.com

[system232]

Change the Hosts file and see if that makes any difference. Hosts should be in your /etc folder. If not just create one (text format) with the following contents:

#########

127.0.0.1 localhost
255.255.255.255 broadcasthost
::1 localhost
fe80::1%lo0 localhost


### ipod/iphone ###
# 74.208.105.171 gs.apple.com
74.208.10.249 gs.apple.com
# 74.208.*.* gs.apple.com

Thanks a lot for the info.
Even this didn't work I am puzzeled I feel there is something wrong with this specific phone since I am not able to downgrade with SHSH to 4.1 and TU but I can do it with my 3g. I am not sure if Apple has something installed in the new phones to block them somehow.
The only other thing I can think of is my internet router but if that is the case how did my 3g phone downgraded properly!!!
I will try to go to apple to replace it and give it a shot.

thanks again