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.
dude you posted 3 replies with the same ****, we all have this issue
thank you a lot! my ipad is back!!! (im from brazil)
Thanks so much for your recommendation ZT21, got my iPad mini 4 up from endless reboot cycles. Problem started when updating to iOS11 from iOS10.3.3 via iTunes Windows 10.
when installing ios 11 there was an error 3503 and stopped doing the screen (((is it all so or just me ??
same here
didnt update on windows 10 also
Thanks ! It's work for me, my device can get out from recovery mode !!
thanks very much, this method works for my ipad!
I HAVE THE SAME PROBLEM TRIED EVEN FROM A DIFFERENT CPU NOTHING
OMG thank you ZT21!! my ipad is finally de-bricked.
I have same issue just happened in yesterday but before that day it's worked fine , any news about this issue fixed or not ?
Still can't restore my iPhone 7.
Countless Live chats and diagnostics later and still nothing.
Maybe it's time for a trip to the Apple Store?
99,95€ for what exactly?
WTH. Same error code 3503. Ipdad pro. Nothing works..... How do we fix this?
I am having same issue one of the IPOD.Please suggest if any alternative.
any idea what error 3503 is?
