Flutter share_plus Crash on iOS 26: The sharePositionOrigin Fix

If your Flutter app’s share button suddenly started crashing on iOS 26, you’re not alone. Here’s what happened and how to fix it.

The Problem

When using the share_plus package to share files or text on iOS, you may encounter this crash:

PlatformException(error, sharePositionOrigin: argument must be set,
{{0, 0}, {0, 0}} must be non-zero and within coordinate space of source view:
{{0, 0}, {440, 956}}, null, null)

This occurs when calling Share.shareXFiles() or SharePlus.instance.share() without providing the sharePositionOrigin parameter.

Why This Worked Before

The share_plus package is the standard way to invoke the native share sheet in Flutter apps. On iOS, the share sheet is a UIActivityViewController that presents differently depending on the device:

• iPhone: Modal sheet sliding up from the bottom

• iPad: Popover anchored to a specific point on screen

Because iPads use a popover presentation, iOS needs to know where to anchor the popover arrow. The sharePositionOrigin parameter provides this—a Rect defining the source location.

Historically, this parameter was only required on iPad. iPhone apps could omit it because the modal presentation doesn’t need an anchor point.

What Changed in iOS 26

Apple now validates sharePositionOrigin on all iOS devices, including iPhones.

If you don’t provide a valid non-zero rect, the share sheet crashes with a PlatformException. This was reported to the share_plus team in August 2025 (GitHub issue #3645) and fixed in version 12.0.1.

Why Testing Didn’t Catch It

I had both HayTracker and PropaneTracker in the App Store and Google Play with working export functionality. I tested before release:

• AirDropped exports from both apps to my MacBook

• Saved exports directly on my development iPhone

• Verified exports on Android devices

Everything worked. The crash only appeared after updating my test iPhone to iOS 26.

The issue is timing: I tested on an older iOS version before Apple introduced the stricter validation. Once iOS 26 rolled out, the missing sharePositionOrigin caused crashes for users who had updated.

The Fix

Always provide a sharePositionOrigin parameter:

import 'dart:ui';
import 'package:share_plus/share_plus.dart';

await Share.shareXFiles(
  files,
  subject: 'My Export',
  sharePositionOrigin: const Rect.fromLTWH(0, 0, 100, 100),
);

The rect values don’t need to be precise for iPhone since it uses modal presentation anyway. They just need to be non-zero. Rect.fromLTWH(0, 0, 100, 100) works fine.

For better UX on iPad, anchor the popover to the actual button that triggered the share:

final box = context.findRenderObject() as RenderBox?;
final sharePositionOrigin = box!.localToGlobal(Offset.zero) & box.size;

await Share.shareXFiles(
  files,
  sharePositionOrigin: sharePositionOrigin,
);

Alternative: Update share_plus

If you update to share_plus version 12.0.1 or later, the package handles this internally and won’t crash on iPhones even without the parameter. However, you should still provide sharePositionOrigin for proper iPad support—it has always been required there.

Complete Example

Before (crashes on iOS 26):

await Share.shareXFiles(
  files,
  subject: 'Export Data',
);

After (works on all iOS versions):

import 'dart:ui';

await Share.shareXFiles(
  files,
  subject: 'Export Data',
  sharePositionOrigin: const Rect.fromLTWH(0, 0, 100, 100),
);

Key Takeaways

1. Always provide sharePositionOrigin when using share_plus on iOS, even for iPhone-only apps

2. iOS 26 introduced stricter validation that breaks previously working code

3. Test on beta iOS versions when possible, especially before major releases

4. The fix is minimal—just add a non-zero Rect parameter

---

References

• GitHub Issue #3645: iOS 26 Unhandled Exception: PlatformException

• GitHub Issue #3685: SharePlus.instance.share fails in iOS 26

• share_plus package on pub.dev

---

This issue affected both HayTracker and PropaneTracker, two Flutter apps I built using Planning-Driven Development. The fix was a one-line change in each app.