It's an issue with the TSS server. It gives the following output:
Sending TSS request attempt 1... TSS server returned: <html>
<head><title>403 Forbidden</title></head>
<body bgcolor="white">
<center><h1>403 Forbidden</h1></center>
<hr><center>Shield</center>
</body>
</html>
Basically, it's on Apple's side. It's NOT an issue with your devices. Just wait a little while for them to fix it.
Help me! I've just downgraded my ipad to 10.3.3 but have trouble. so I restore it again but the error 3503 appears.
I can't restore. anyone can help to fix.
Thanks ZT21 for that iMyFone app link
it worked on my apple tv 4 after a bad restore process with error 3503
I use 3u tools to exit the dfu mode or recovery mode and my iphone can be use again
Solved it in my case (IPad2), 3utools, only had to hit the auto-activate button during connect and got my IPad back working.
Download 3uTools. It's free and I was able to fix mine just now. Don't bother with the other apps that makes you pay.
I have two windows machines, both have the same problem. 3utool has shsh error
Hayir Iphone 4s telefonum ve restore yapdigim zaman hata (3503) aliyorum.
any idea what error 3503 is?
