Apple has stopped signing the iOS 8.1 firmware, which means you cannot downgrade from iOS 8.1.1 and jailbreak. Thankfully, the TaiG jailbreak is iOS 8.1.1 compatible and you should probably upgrade and jailbreak.
Until recently, if you upgraded to iOS 8.1.1 by mistake and lost your jailbreak, you could simply downgrade to iOS 8.1 since Apple was still signing it. As of yesterday, that came to an end. If you somehow missed out on iOS 8.1, you’ll need to upgrade to iOS 8.1.1 directly. And if you want to jailbreak, you could do so with the new TaiG iOS 8.1.1 jailbreak.
MuscleNerd also posted that the TaiG jailbreak is safe to use, if you uncheck the box that says 3K 1.0.0. We recommend that if you’re not on iOS 8.1.1, you upgrade right away and jailbreak using TaiG. It is always best to stay on the latest firmware on devices that are compatible. The TaiG jailbreak also supports iOS 8.2 beta, but it has only been giving errors with that firmware so far. Maybe Apple has patched the exploit in iOS 8.2 or maybe the TaiG team is waiting for Apple to release iOS 8.2 to the public and then add support for iOS 8.2?