Apple today released an updated version of iOS 17.6.1, with the new software coming a week and a half after the launch of the original iOS 17.6.1 update. The new version has a build number of 21G101, up from 21G93.
iOS 17.6.1 can be downloaded on eligible iPhones and iPads over-the-air by going to Settings > General > Software Update.
According to Apple's release notes, the iOS 17.6.1 update addresses an issue that could prevent the enabling or disabling of Advanced Data Protection. It is not clear what is different between the new version of the software and the original version.
This update includes important bug fixes and addresses an issue that prevents enabling or disabling Advanced Data Protection.
The Advanced Data Protection bug impacted a small number of users. Those who tried to turn Advanced Data Protection on and weren't able to get it enabled saw an error message and it was clear it wasn't active. Affected users who tried to turn it off saw it disabled in the interface, though it was actually still active for iCloud data.
Both of those bugs have been fixed in the update. iPhone users who had the bug that prevented Advanced Data Protection from properly turning off will see a notification that asks them to confirm the decision to turn the feature off after installing iOS 17.6.1. Apple says that the few users who experienced this bug had an expected level of security or more, in the situation where ADP did not turn off as expected.
Update: The re-released iOS 17.6.1 update is available over the air on devices that are updating from older versions of iOS, including iOS 12 and iOS 16. If you already had iOS 17.6.1 installed or another version of iOS 17, you will not see the update with the 21G101 build number, nor will devices that have iOS 13, iOS 14, or iOS 15 installed. It fixes an issue that could prevent access to Apple Fitness+.
