Hello,
We’ve been using the CesiumJS WebGL library for several years, both on our website and within embedded WebViews in our iOS application. Since upgrading to iOS versions 18.2 and 18.3, we’ve started receiving numerous user complaints regarding application crashes on various iPad and iPhone models when loading CesiumJS.
The crashes occur as soon as the 3D view initializes, and the error consistently reported is:
"WebGL context lost"
This issue appears to be a WebGL-related crash potentially triggered by GPU memory handling or allocation limits. However, we are not detecting any abnormal memory consumption prior to the crash, and the same setup works perfect on older iOS versions and on all Android devices and versions.
Steps to Reproduce:
Open: https://www.flightradar24.com/30.47,-94.84/8
Click on any aircraft icon on the map.
In the aircraft details panel at the bottom, click on the “3D view” tab.
On iOS 18.2 or 18.3, the page will crash shortly after initializing CesiumJS WebGL.
Affected Devices:
This issue is occurring across a wide range of devices, including:
iPad 9th Generation
iPad Pro (11-inch, 2nd Gen)
iPhone SE (2020 and 2022)
iPhone 11, 11 Pro
iPhone XR
iPhone Mini
All of the above are running iOS 18.2 or 18.3. The problem does not occur on Android or previous iOS versions.
Request:
Has anyone else encountered similar issues with WebGL context loss after upgrading to iOS 18.2 or 18.3? Are there any known changes in memory limits or WebGL behavior in these recent iOS updates? We’d appreciate any insight or suggestions on workarounds or potential fixes.
Thank you!
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I have a basic setup following WWDC 2020 on Safari Web Extensions and another one on XPC. The video even mentions that one can use UserDefaults or XPC to communicate with the host app. Here is my setup.
macOS 15.2, Xcode 16.2
A macOS app (all targets sandboxed, with an app group) with 3 targets:
SwiftUI Hello World
web extension
XPC Service
The web extension itself works and can update UserDefaults, which can then be read by SwiftUI app - everything works by the book.
The app can communicate to the XPC service via NSXPCConnection - again, everything works fine.
The problem is that the web extension does not communicate with XPC, and this is what I need so that I can avoid using UserDefaults for larger and more complex payloads.
Web Ext handler code:
class SafariWebExtensionHandler: NSObject, NSExtensionRequestHandling {
func beginRequest(with context: NSExtensionContext) {
// Unpack the message from Safari Web Extension.
let item = context.inputItems[0] as? NSExtensionItem
let message = item?.userInfo?[SFExtensionMessageKey]
// Update the value in UserDefaults.
let defaults = UserDefaults(suiteName: "com.***.AppName.group")
let messageDictionary = message as? [String: String]
if messageDictionary?["message"] == "Word highlighted" {
var currentValue = defaults?.integer(forKey: "WordHighlightedCount") ?? 0
currentValue += 1
defaults?.set(currentValue, forKey: "WordHighlightedCount")
}
let response = NSExtensionItem()
response.userInfo = [ SFExtensionMessageKey: [ "Response to": message ] ]
os_log(.default, "setting up XPC connection")
let xpcConnection = NSXPCConnection(serviceName: "com.***.AppName.AppName-XPC-Service")
xpcConnection.remoteObjectInterface = NSXPCInterface(with: AppName_XPC_ServiceProtocol.self)
xpcConnection.resume()
let service = xpcConnection.remoteObjectProxyWithErrorHandler { error in
os_log(.default, "Received error: %{public}@", error as CVarArg)
} as? AppName_XPC_ServiceProtocol
service?.performCalculation(firstNumber: 23, secondNumber: 19) { result in
NSLog("Result of calculation XPC is: \(result)")
os_log(.default, "Result of calculation XPC is: \(result)")
context.completeRequest(returningItems: [response], completionHandler: nil)
}
}
}
The error I'm getting:
Error Domain=NSCocoaErrorDomain Code=4099 "The connection to service named com.***.AppName.AppName-XPC-Service was invalidated: failed at lookup with error 3 - No such process."
What am I missing?
After updating to iOS 18.4, our web application (with service workers) crashes on devices that accessed it prior to the update. This issue also affects hybrid mobile apps using the same web application; reinstalling the app resolves it by refetching and reinstalling service workers. Debugging is challenging because clearing the cache or reinstalling the app fixes the problem, and no useful error logs are available. Has anyone encountered similar crashes related to service workers after an iOS update and have any insights into the cause?
I am trying to build and run a Safari Web Extension from Xcode and I have enabled "Allow unsigned extensions" in Safari settings. However, I see the below pop up:
And, if click on the "Quit and Open Safari Extensions Preferences..." button, the project stops running on Xcode and nothing happens.
What can be the issue? The extension works and runs fine if I get it from the Mac App Store and this only happens when running from Xcode. I even tried completely uninstalling the mac app store version and still facing the same issue.
Please update Accessibility OS Settings for VoiceOver in iPhone iOS and iPadOS to include frames on the Rotor, and to make web navigation and component gestures easier to find and assign. Please add content to the iPhone and iPad Apple User Guide to use VoiceOver in web navigation with touch gestures.
Specifically... iframes.
There is no clear guidance in Apple documentation for VoiceOver users in iPhone or iPadOS to access iframes with touch gestures. A common belief as written on AppleVis, other blogs, and internet searches is that iframes in Safari or a webView in an app are only available with explore by touch.
If explore by touch is the only option for some interactions, that needs to be included in Apple User Guides. If not, details on equivalent touch gestures for VO that have keyboard interactions in Mac need to be clear for users.
VoiceOver for Mac includes a default keyboard interaction of VO-Command-F in its extensive User Guide (https://support.apple.com/guide/voiceover/by-images-or-frames-mchlp2740/mac). A user can include a rotor option for web navigation for iframes.
VoiceOver for iPhone and iPad does not include a default swipe gesture assigned to frames. An option is not available for the Rotor.
While there is iPhone User Guide guidance that gestures can be customized (https://support.apple.com/guide/iphone/customize-gestures-and-keyboard-shortcuts-iph59a8e6fd2/18.0/ios/18.0), it is not clear that for adding this gesture, "Move to the next frame" is tucked into the advanced navigation commands for VoiceOver Accessibility Settings in the OS. At least in my phone, the word "frame" was not searchable despite the All Commands screen using a search bar.
So I have web Augmented Reality apps hosted on AWS S3. It worked fine for a month, but as soon as the IOS 18.4 update was installed they stopped working. It works on every other device and IOS versions.
The URLs for the mentioned AR experiences:
digitechonline.in/solsprefimaginewt8/
digitechonline.in/solsprefimaginewt8p2/
digitechonline.in/orocarear/
These AR experiences get stuck on the loading screen and either reload or give an error. Ideally the camera is supposed to open.
I have tested it on Safari, Microsoft Edge and Google Chrome browsers.
They were created through Unity webgl and hosted on AWS S3 bucket. Please provide a quick solution to this.
When a DNR rule is set for a specific URL and the request receives a server-side redirect (e.g., 302) to a different URL that does not match the urlFilter, the rule still seems to apply to the redirected request. We are using macOS 15.4 and Safari 18.4.
For example, consider two sequential calls: call1 and call2.
call1 triggers a 302 redirect to call2.
A DNR rule is created to add a "Cookie" header to call1 based on its URL.
Unexpectedly, the same cookie is also added to call2, even though call2's URL does not match the rule's urlFilter.
This results in the Set-Cookie response from call1 being ignored, and call2 receiving the manually set cookie instead—leading to incorrect behavior.
This issue doesn't occur in Chrome or Firefox, where the rule is not applied to the redirected request if the URL no longer matches.
We are looking for assistance in fixing these issues and having our Safari Extension function the same as it does in Firefox and Chrome.
We’re seeing an issue in our Safari Web Extension where not all cookies from the Set-Cookie response header are accessible. We are using macOS 15.4 and Safari 18.4.
In the webRequest.onHeadersReceived callback, the Set-Cookie header returned by Safari only includes some of the cookies set by the server. If multiple Set-Cookie headers are present, we seem to receive only a partial list, some cookies are missing entirely.
In Chrome and Firefox, the same callback provides all cookies set by the server without issue.
We are looking for assistance in fixing these issues and having our Safari Extension function the same as it does in Firefox and Chrome.
We’re encountering an issue when trying to add non-standard headers to outgoing requests using Declarative Net Request (DNR) rules in our Safari Web Extension.
Tested on macOS 15.4 with Safari 18.4.
Specifically, when attempting to add a custom header such as "X-Custom-Header" using a DNR rule, the header does not appear in the request. We are able to add standard headers like "Authorization" and "Cookie" to the request successfully using the same method.
This behavior suggests that Safari may be filtering or blocking non-standard headers when set via DNR rules, unlike other browsers.
In Chrome and Firefox, the same rule adds the "X-Custom-Header" header without any issue.
We are looking for assistance in fixing these issues and having our Safari Extension function the same as it does in Firefox and Chrome.
Safari Extension Error: “Non-persistent background content cannot listen to webRequest events.” after macOS 15.4 / Safari 18.4 Update
We’re seeing the following error in the Safari Extensions tab after updating to macOS 15.4 and Safari 18.4:
“Non-persistent background content cannot listen to webRequest events.”
This error did not appear prior to the update, and we haven’t found any official documentation stating that webRequest API is no longer supported in Safari.
In our extension (Manifest V3), we are using the webRequest.onHeadersReceived callback to intercept response headers and read updated cookies.
While the functionality itself still works as expected. we’re able to access the response headers and this error is now shown in the Extension settings page.
We are not seeing this issue in other browsers (Chrome, Firefox) using the same Manifest V3 setup.
Is there any plan to deprecate webRequest support in Manifest V3 for Safari?
We’d appreciate any clarification or guidance on how to handle this going forward.
Howdy,
WKWebView feature request: allow Fullscreen API without User Gestures
similar to ElectronJS' userGesture: true flag that allows devs to bypass user gesture restriction for Fullscreen API and similar
executeJavaScript(code[, userGesture])
https://www.electronjs.org/docs/latest/api/web-contents#contentsexecutejavascriptcode-usergesture
afaik this is allowed because of a fairly recent update to Chromium that also allows users to give Fullscreen API permissions per domain
https://chromeos.dev/en/posts/using-the-fullscreen-api-without-gestures
Would be greatly useful for a use case in my cross-platform app, so I can avoid rewriting all platforms to use Chromium
Thanks
I’ve been working on a personal iOS project for fun — essentially a YouTube music player, learning how background media playback works in native iOS apps.
After seeing that Musi (a famous music streaming app) can play YouTube audio in the background with the screen off — I got really curious. I’ve been trying to replicate that basic background audio functionality for YouTube embeds using WKWebView. I've spent a crazy amount of time (probably 20 hours) trying to figure this out but have achieved no success.
Here’s what I’ve tried so far:
-Embedding a YouTube video in a WKWebView
-Activating AVAudioSession with .playback and setting .setActive(true)
-Adding the UIBackgroundModes key with audio in Info.plist
-Adding the NSAppTransportSecurity key to allow arbitrary loads
--Testing on a real device (iPhone 14, iOS 18.1 target)--
What happens:
Audio plays fine in the foreground.
If I exit the app and go to the lock screen quickly enough (less than 3 seconds) after pressing play, I can resume playback briefly from the lock screen — but it doesn’t automatically continue like in Musi and other apps like it.
Most of the time, the audio stops when the app is backgrounded.
I get this error consistently in the logs:
Error acquiring assertion: <Error Domain=RBSServiceErrorDomain Code=1 "(originator doesn't have entitlement com.apple.runningboard.assertions.webkit AND originator doesn't have entitlement com.apple.multitasking.systemappassertions)"
It seems like the app lacks some specific entitlements related to WebKit media playback. I don’t have AppDelegate/SceneDelegate (using SwiftUI), but can add if needed.
I’m super curious how music streaming apps using youtube as a source get around this — are they doing something different under the hood? A custom player? A SafariViewController trick? Is there a specific way to configure WKWebView to keep playing in the background, or is this a known limitation?
Would really appreciate any insight from folks who’ve explored this before or know how apps like Musi pulled it off.
Thanks in advance!
Hi! We are having a hard time with the universal link, help is appreciated! Thanks in advance!
The universal link doesn't work after installation for some time. A user has to wait for from 5 to a couple of hours after the app is installed on the device.
This has also affected App reviewers since we need the universal link to work for successful login. Each submission will receive a rejection of we cannot login and it will be approved until we kindly ask them to try again.
I believe the JSON is delivered to devices by Apple's CDN system and the fact that it works on most devices most of the time should imply that we have a valid apple-app-site-association setup.
So I am really confused about the wait time, which is giving us trouble with app review and a bad user experience
updateDynamic rules is blocking ads on my device with iOS 17.4, but on my iOS 18 device the same code is not blocking ads.
Is this a known issue?
I am running Appium tests on an iOS 18 simulator, and I am encountering an intermittent issue where the device screen gets locked unexpectedly during the tests. The Appium logs show no errors or unusual activity, and all commands appear to be executed successfully.
However, upon reviewing the device logs, I see entries related to the lock event, but the exact cause remains unclear.
SpringBoard: (SpringBoard) [com.apple.SpringBoard:Common] lockUIFromSource:Boot options:{
SBUILockOptionsLockAutomaticallyKey: 1,
SBUILockOptionsForceLockKey: 1,
SBUILockOptionsUseScreenOffModeKey: 0
}
SpringBoard: (SpringBoard) [com.apple.SpringBoard:Common] -[SBTelephonyManager inCall] 0
SpringBoard: (SpringBoard) [com.apple.SpringBoard:Common] LockUI from source: Now locking
Has anyone experienced similar behavior with Appium on iOS 18, or could there be a setting or configuration in the simulator that is causing this issue?
I want to migrate from a Safari App Extension to a Safari Web Extension, but don't know how to get rid of the message, telling users that my extension can access their passwords. Here is a message which I see:
I was thinking that this might be because all Safari Web Extension get this type of access, but I have a Safari Web Extension which does not require such level of access:
Here is the manifest:
{
"manifest_version": 2,
"default_locale": "en",
"name": "__MSG_extension_name__",
"description": "__MSG_extension_description__",
"version": "1.1",
"icons": {
"48": "images/icon-48.png"
},
"background": {
"scripts": [
"background.js"
],
"persistent": true
},
"browser_action": {
"default_popup": "popup.html",
"default_icon": {
"16": "images/toolbar-icon-16.png"
}
},
"permissions": [
"nativeMessaging", "tabs"
]
}
and here is the Info.plist file:
Here is the entire code of the extension:
https://github.com/kopyl/web-extension-simplified
We are encountering a download issue in Safari 18.2 on macOS Sequoia 15.2 where file downloads initiated by our AngularJS application (such as Excel exports) are silently blocked.
There are no errors in the browser console, and the download does not occur.
Interestingly, after testing on Safari 18.3 with Sequoia 15.3, the downloads worked as expected.
However, the problem reappeared on Safari 18.4 with Sequoia 15.4.
We suspect that recent changes in Safari’s security or download handling may be preventing downloads triggered via asynchronous JavaScript (e.g., AJAX calls) that are not initiated directly by user interaction.
We would appreciate any insights, suggestions, or possible workarounds from the community. Looking forward to your guidance on this matter.
Since the transition to iOS 18.4, we have been having an issue where when loading an m3u8 file specified in the src attribute of a video tag in WKWebView, the ts file is loaded repeatedly.
Are there any good ideas for this?
Also, if there have been any changes to the specifications of WKWebView, we would appreciate it if you could let us know.
Hi, I'm using a webview in Swift, where I load an html file locally. Basically I have an angular project built and loaded directly into my app bundle. The webview requires the use of the camera. I request permissions via and javascript, the pop-up appears, I accept the permissions and the app works correctly. Only that after a certain number of seconds, the permissions are requested again. It's as if the webview doesn't cache the accepted permissions.
Is this normal behavior?
I am using Angular version 14
Topic:
Community
SubTopic:
Apple Developers
Tags:
Safari Developer Tools
Safari Services
Safari and Web