iOS 9.3 - Safari/Mail freezes after clicking links on iPhone 6S

Ben does explain the background, as well. In brief, it seems to have started with a simple coding practice of just adding valid web links for apps that aggregate...like Booking .com, or my Newsify app example. That worked up to a point, but when the list got huge it then overloaded an iOS routine and either crashed things as he says so that the daemon couldn't disgorge the huge lump of info. Or maybe it was an unintentional loop, or an off-by-one, or a memory allocation glitch. So the effect spread beyond the app and affected Safari, and other things that the iOS touched for web links. If people did a clean install that really cleaned things up for the daemon, and avoided reintroducing the link-happy apps' oversized lists-o-links, it might work out. Whatever the case, here is Ben's explanation:

"What's Going On

In iOS 9 Apple introduced Universal Links, these allow app developers to associate their website and app, so links to the website can open the app up automatically if installed. For example, following a link to a Guardian article opens up the Guardian app to that specific article instead of their website.

App developers put an app association file on their website which lists which types of URLs the app can open. When you install an app, iOS downloads this associated file and updates your own database of what URLs your installed apps can open. The website and app listing in iTunes are linked by the developer - so it prevents anyone from hijacking your website with their app.

When you tap a link in iOS, the system looks through the database of installed apps supported URLs to see if it matches a pattern an installed app can handle. If nothing matches it opens it up as a standard app.

Why's It Broken

It looks like there's a bug in iOS that completely breaks the Universal Links if it gets served an app association file that's too large.

Benjamin Mayo of 9to5mac.com reported installing the Booking.com app consistently broke their test devices - which led Steve Troughton-Smith (who else...) to take a peep at their association file: [screenshot of the file, and screenshot of Twitter where Steve T-S states that the file was a 2.3MB download].

It seems that the large size of their file, due to it having every URL from their website inside it breaks the iOS database on the device. Apple allows you to have pattern based matching, so instead of having to include every hotel's URL in the association file, Booking.com could just put /hotel/* to match all the hotels on their site.

Whilst Booking.com aren't following the recommended approach, it's not their fault that a third-party can break a fundamental system feature like web browsing. Apple should be handling these edges graciously.

The worst part - deleting the app doesn't clear the Universal Link association. Because the OS process that handles the Universal Links has crashed, it appears unable to remove the corrupt database.

The Workarounds

Unfortunately there's no fix for this at the moment although a restart of the OS can temporarily restore links, and turning off JavaScript (Settings -> Safari -> Advanced) allows certain websites, such as Google search results to work again. Apple confirmed these workarounds to me, and hinted there may be a software update to resolve this;

'Be sure to keep your software up to date in case a future release addresses this issue.

We do have two workaround options. Restarting the phone may allow links to work, but the issue can come back. The other workaround would be [to] turn off JavaScript.'

Some users have been able to fix with an elaborate reboot cycle

Update One 13:00 March 28/03/2016: Booking.com have updated their association file - it's now only 4KB - this hasn't fixed the issue but should prevent new users that install from hitting the same problem. Even reinstalling the app and rebooting doesn't fix it - the swcd (shared web credentials daemon) crashes once it's got corrupt data in it."

Several users as of earlier this evening (3/29) at least either thought Ben's method through, or tried something similar:

"The article makes sense. Apparently the universal link database is part of the iTunes backup. That explains why the feature works as the phone was freshly restored back to a clean 9.3. But it fails as soon as a restore from iTunes backup was done. The corrupted DB was put right back in place. One almost has to have a "clean" backup in order to get it back to working order. If this proves to be the root cause, may be they should consider allowing an option to restore data only in iTunes backup. I stay away from a clean resinstall because I'll lose thousands of iMessages. Most of other things like mail and contacts are restored once you log in to iCloud but not iMessage. I think there is a way to download all the apps purchased on App Store on to a freshly restored new phone (at least I have done it once over the last couple days during all the experiments I did). So getting only all my messages back in a restore works for me. Well, this is just my situation. I'm sure others may need other options. Hope they fix this soon. Just amazed that Apple engineers overlooked a simple file size test if a huge association file did corrupt their DB. It almost like they focus so much on protecting from malicious intends, they let in a careless mistake."

"I did similar to get my phone working again

backed up photos to iPhoto on mac

(backed up my current phone through iTunes for a later date when a fix comes out)

erased phone from the phone

restored from a backup pre 24.03.2016

immediately put phone into flight mode before the apps started downloading back onto the phone

deleted the offending apps before they caused any hassle and were greyed out still

came out of flight mode

allowed the apps to download i was keeping

working now"

"I dowloaded iOs 9.2.1 through https://ipsw.me/

Installed this .ipsw file in iTunes

Hold the Alt key (on Mac OS X) / the Shift key (on Windows) and hit “restore” in iTunes

iOs Restore went ok but all data is gone from the iPhone

Restore from backup does not work because the latest backup was with iOs 9.3

On my iMac I restored the MobileSync backup folder (1 day before upgraging to 9.3) via Time Machine (~\library\Application Support\MobileSync\Backup\)

Long live Time Machine!!!

Now I could restore my iPhone from backup

Everything works fine again

Waiting for the upgrade "

"SOme people can't really do that since we use OTA backup to icloud...

I stopped using a pc to do my backups years ago because I keep changing laptops practically every month or so (work related, gotta keep up with the latest and greatest tech) and I was just chewing through my activated devices faster than apple could release them....

I have lost en contracts and money as it is now. "

<Link Edited by Host>

And a couple used similar methods, or Ben's. One used a method from a source that inspired Ben's:

"I have been following this whole thread and I am happy to report that Inhave fixed the issue. I waited for 24h before posting to make sure this still works.

You do not need to revert to a previous version or lose any backups. I have 300 apps on my phone and I kept all of them (except 3), including my full backup.

No iTunes.

The process I followed:

1. Create an iCloud backup.

2. Erase all content and settings.

3. Follow the process to restore from the iCloud backup once the phone has been wiped.

4. As soon as your applications show up greyed out (which means they are queued to be downloaded), click and hold any app so you can delete the offending applications BEFORE they install. In my case, and I suspect for many other people, the offending apps I deleted were:

- Booking.com

- Triparvisor

- Yelp

The rest of my apps downloaded and the issue did not return."

3/29 "I followed exactly the steps from here; and the problem went away. There are a good description of the problem here;

If you don't want to use iTunes for syncing the booking.app, you can use xcode. Open xcode and choose window->devices. Then choose your i-device and press the '+' button under installed apps."

Note: if you look through the versions that Ben lists, you should get to the version where someone was inspired to experiment with xcode.

<Link Edited by Host>

Tried downgrading back to 9.21 and realized that I cannot restore all the apps/photos etc because It has been sync to 9.3 ... darn..

There were a LOT of other ideas. Bravo, people.

DNS?

"On my last check i tried to see if it was related to DNS resolving (since I use google's dns) but ofc it is not."

Connection? (phone doesn't connect to Chevrolet, 9.3 was supposed to fix)

"I have been battling 9.X.X and it not working with my new truck since I updated to it and apple keeps blaming it on Chevrolet, which oddly enough worked perfect until the day I updated to the 9.x.x.

Long story short, I heard 9.3 was suppose to fix this "Chevrolet" issue so against my better judgement I upgraded as soon as it was available...."

Chjp?

"...I ask in the community, is there ppl who are experiencing problems with iPhone and TSMC chip inside?

Hoping to solve it ASAP, I use my iPhone in tethering and i browse the web with my MacBook Pro retina... what else shall I do?"

Response: "TSMC chip AND the bug present on 6s with 9.3"

Response: "N71mAP TSMC chip in mine also"

Response: "There is no hardware that can be replaced to fix this issue. (There is no "loading safari" component)

A restore and setup as new is a very viable and useful troubleshooting step.

Like it or not software issues are affected by use. Not saying the phone was abused but data was added that was not there when the box was opened.

If the issue persists after a restore and set up as new then it is likely a server issue (For safari suggestions for example) or an IOS issue.

Neither of those can be fixed instantly."

And reply: "when i asked if it was about iPhone 6s A9 chip (whether samsung or tsmc) it wasn't cause i thought it was hardware issue, besides the little differences that the firmware might have related to the risc cpu installed. Now anyway we can see it's happening on both hardware so this is not helpful."

Certificates?

"I think more in line of certificates being out of date somewhere. Mainly because the non-secure page of Google is working fine: http://www.google.com/webhp?nord=1"

Other suspicions: malware, the change to Daylight Savings Time in Europe, and some other thoughts...

I do sincerely hope categorizing a bit helps Apple.

I am told by a worried government user that a government IT department (which shall remain nameless) is insisting on an update for iOS on iPhones.

Ironically, their deadline for users to comply is said to be this Friday (April Fools Day - probably not intentional).

Same issue here from Singapore.

Hope they release a patch soon.

This is frustrating

I'm having the same problem and also having the problem with my iPad. so this *****

Thanks! That fixed it - can hold me over until they post a proper patch

This is really annoying I thought my phone is broken, iOS9.3 has been downloaded but not been installed on my iphone yet, that already is happening the jam. Hope APPLE can fix it sooner!

I refuse to use iCloud. It isn't even enabled on my (currently useless) phone.

II've never had booking.com (or any travel app) on my iPhone and I have this issue. My phone freezes on links in safari, chrome and multiple apps. It's pretty much useless. This has nothing to do with booking.com app 😟

I have the same issue: iphone6 128GB. My phone is showing that I am still running 9.2.1, however I have downloaded the 9.3 update but not installed it. I am unable to open any links from safari, Firefox or email, or any app that has hyperlinks since yesterday. Frustrating beyond belief. Get it sorted Apple, I've had so many problems with this iPhone that I'm tempted to jump ship to Samsung when my contract is up (4 months away).

II've never had that ap- but I have the issue.

WE need to let people know about this thread. The larger the number that report the issue the more likely it is to bolster Apples efforts to resolve it. I'm sure we are only a small percentage of the impacted people that have the issue.

USe twitter, FB or whatever. Have people speake up.

FIx please.