iOS

Apple unsigns iOS 18.6, preventing downgrades from iOS 18.6.1 or 18.6.2

iOS 18 downgrade.

Apple stopped signing iOS 18.6 on Thursday, just one week after releasing iOS 18.6.1 alongside watchOS 11.6.1 to enable the Blood Oxygen monitoring feature on Apple Watches that were previously barred from offering the feature to end users under an International Trade Commission ruling – but later circumvented by a U.S. Customs and Border Protection ruling that patent troll Masimo is now once again suing over.

Masimo sues U.S. Customs and Border Protection in bid to block green light to enable blood oxygen monitoring on Apple Watches

Apple Watch Ultra 2 on desk with blood oxygen sensor LEDs active

When Apple released iOS 18.6.1 and watchOS 11.6.1 last week, bringing Blood Oxygen monitoring to previously excluded models following a U.S. Customs and Border Protection approval that allowed Apple to move forward with the “redesigned” experience on those devices, we had a gut feeling that patent troll Masimo wouldn’t let that go very far without a fight.