iOS 5.1 has officially been released less than 2 days ago and Apple has already blocked the possibility to restore to the old iOS 5.0.1. If you open TinyUmbrella now and try to save an SHSH by directing the program to Apple's servers you will be met with the message above which basically tells you that you cannot do this. Those from the Dev Team they warned us that this would happen extremely fast after the release of iOS 5.1 and here they were right this time, so it would be better not to restore now, especially if you have an iPad 2 tablet or an iPhone 4S.
Considering that on iOS 5 the restore/downgrade situation is very complicated, I will explain the situations in which you can downgrade/restore to an old version of iOS.
- iPhone 4S – you can ONLY restore to iOS 5.1, even if you have SHSHs for iOS 5.0.1. For now those SHSHs are useless.
- iPad 2 – if you have SHSH for iOS 4.x you can ONLY restore to those versions and to the new iOS 5.1. Any other SHSHs for iOS 5.0.1 are completely useless.
- iPhone 3GS/4, iPad 1, iPod Touch 3G/4G – you can restore to any version of iOS for which you have SHSH saved!
If a bootrom exploit is discovered for iPhone 4S and iPad 2, then restoring to iOS 5.0.1 will be possible, but until then you cannot do this.
