Since posting our original story, we have heard from a lot of readers that are affected by iOS 9 crashes or app hangs when tapping links, spanning multiple iOS versions (not just 9.3) and devices. In a statement, Apple has now confirmed that they are working on a fix for the problem, coming in a software update (presumably iOS 9.3.1).
“We are aware of this issue, and we will release a fix in a software update soon.”
Previously, we pinpointed Bookings.com as a cause of the bug, although noting it affects other apps as well. On Twitter, it was found that their website association file, used by the system for the universal links feature introduced with iOS 9, was many megabytes, grossly oversized. This would essentially overload the daemon that had to parse these files, causing the crashing. The Bookings.com app has since corrected its payload file to be a far more reasonable 4 kilobytes. Users of Bookings.com should delete and reinstall the app, to refresh the system caches for the URL association file.
However, Bookings.com is not the only case of a developer misusing the API, so people who continue to experience bugs will also find that they have other apps installed on the system which are also registering thousands of URLs. Unfortunately, it is practically impossible to find out which apps are the misdemeanours. In terms of high-profile cases, we have heard that Wikipedia and Eat 24 are among the apps registering too many domains in their universal link directory. Sources tell us that Apple is working with high-profile developers to help them understand and better use the universal links APIs. The forthcoming software update will presumably let iOS better handle huge payloads files, rather than just crashing on the spot.
Apple did not say when it expects to release the software update, other than ‘soon’. As it is an issue affecting so many people (and disrupting a rather major activity people do on iPhones and iPads, tap links) however, it would not be a surprise to expect a bug fix within a few days.