LatLng is not finite: LatLng(latitude:NaN, longitude:NaN) from map_interactive_viewer.dart

[matisiekpl]

What is the bug?

Map is stuck and stacktrace is thrown:

_Exception: Exception: LatLng is not finite: LatLng(latitude:NaN, longitude:NaN)
#0      Crs.checkLatLng (package:flutter_map/src/geo/crs.dart:82)
#1      Epsg3857.latLngToOffset (package:flutter_map/src/geo/crs.dart:189)
#2      MapCamera.projectAtZoom (package:flutter_map/src/map/camera/camera.dart:278)
#3      MapCamera.offsetToCrs (package:flutter_map/src/map/camera/camera.dart:400)
#4      MapInteractiveViewerState._handleScaleStart (package:flutter_map/src/gestures/map_interactive_viewer.dart:549)
#5      ScaleGestureRecognizer._dispatchOnStartCallbackIfNeeded.<fn> (package:flutter/src/gestures/scale.dart:787)
#6      GestureRecognizer.invokeCallback (package:flutter/src/gestures/recognizer.dart:345)
#7      ScaleGestureRecognizer._dispatchOnStartCallbackIfNeeded (package:flutter/src/gestures/scale.dart:786)
#8      ScaleGestureRecognizer.acceptGesture (package:flutter/src/gestures/scale.dart:809)
#9      _CombiningGestureArenaMember.acceptGesture (package:flutter/src/gestures/team.dart:51)
#10      GestureArenaManager._resolveByDefault (package:flutter/src/gestures/arena.dart:275)
#11      GestureArenaManager._tryToResolveArena.<fn> (package:flutter/src/gestures/arena.dart:255)
#12      _microtaskLoop (dart:async/schedule_microtask.dart:40)
#13      _startMicrotaskLoop (dart:async/schedule_microtask.dart:49)

How can we reproduce it?

git clone https://github.com/matisiekpl/flutter_map_supercluster
cd flutter_map_supercluster/example
flutter build ios
flutter run ios

# After launching app, go to any map from drawer and try to move in mulitple directions. After few moves, you should get grey screen.

Doctor output:

[✓] Flutter (Channel stable, 3.41.6, on macOS 26.4.1 25E253 darwin-arm64, locale pl-PL)

Do you have a potential solution?

No response

[nisenbeck]

Also experiencing this since upgrading from 8.2.2 to 8.3.0. Downgrading back to 8.2.2 resolves the crash.

I initially suspected NaN coordinates in my app data, but the crash also appears to be reproducible with basic map panning, suggesting this is an internal regression in 8.3.0, potentially related to PR #2182 introducing checkLatLng.

Environment: Flutter 3.41.7, Android (Pixel 9a)

Stack trace:

_Exception: LatLng is not finite: LatLng(latitude:NaN, longitude:NaN)
Crs.checkLatLng (crs.dart:82)
Epsg3857.latLngToOffset (crs.dart:189)
MapCamera.projectAtZoom (camera.dart:278)
TileRangeCalculator._calculatePixelBounds (tile_range_calculator.dart:51)
TileRangeCalculator.calculate (tile_range_calculator.dart:34)
_TileLayerState.build (tile_layer.dart:529)

Second crash path:

_TileLayerState._pruneWithCurrentCamera (tile_layer.dart:750)
Timer._createTimer.<fn>

The camera itself appears to hold NaN coordinates. Two independent code paths hit the same invalid state within milliseconds.

[JaffaKetchup]

This is unexpected! We didn't manage to produce these results in our testing.

An MRE would be helpful which doesn't rely on any external plugins.

[nisenbeck]

After further investigation I was able to identify the trigger and create a MRE:
https://github.com/nisenbeck/flutter_map_mre

Root cause in my app:
I was creating a new CameraFit.bounds instance on every widget rebuild inside my build() method. Combined with calling setState() from onPositionChanged, this caused a rebuild during an active pan gesture. It appears flutter_map 8.3.0 re-applies initialCameraFit when the object reference changes and doing so mid-gesture produces NaN camera coordinates, which then causes the crash.

My fix:
Compute initialCameraFit once and cache it as state, so the same object instance is passed to MapOptions on every rebuild.

I'm not sure whether this is a flutter_map bug or expected behaviour. Creating a new object in build() is arguably bad practice, and the initial prefix implies the value should be stable. However, regardless of the caller's behaviour, a library probably shouldn't produce NaN internal state. I'd be happy to hear your thoughts on this.

Update 2026-04-24:
The fix above reduced the crash frequency significantly, but did not eliminate it entirely. The same NaN crash still occurred through different stack trace paths (e.g. _pruneWithCurrentCamera, _handleTap). I've since downgraded to 8.2.2, which fully resolves the issue.

[RobyMassa]

The same error occurs to us too (flutter_map 8.3.0):
Exception: LatLng is not finite: LatLng(latitude:NaN, longitude:NaN)

=> the problem occurs when quickly zooming in or zooming out

The relevant error-causing widget was:

CustomPaint CustomPaint:file:///home/roby/.pub-cache/hosted/pub.dev/flutter_map-8.3.0/lib/src/layer/circle_layer/circle_layer.dart:57:14
When the exception was thrown, this was the stack:

#0 Crs.checkLatLng (package:flutter_map/src/geo/crs.dart:82:7)
#1 Epsg3857.latLngToOffset (package:flutter_map/src/geo/crs.dart:189:5)
#2 MapCamera.projectAtZoom (package:flutter_map/src/map/camera/camera.dart:278:11)
#3 MapCamera.pixelOrigin (package:flutter_map/src/map/camera/camera.dart:114:24)
#4 MapCamera.getOffsetFromOrigin (package:flutter_map/src/map/camera/camera.dart:308:66)
#5 FeatureLayerUtils.metersToScreenPixels (package:flutter_map/src/layer/shared/feature_layer_utils.dart:118:15)
#6 CirclePainter._getRadiusInPixel (package:flutter_map/src/layer/circle_layer/painter.dart:180:14)
#7 CirclePainter.paint (package:flutter_map/src/layer/circle_layer/painter.dart:65:35)

and

#0      Crs.checkLatLng (package:flutter_map/src/geo/crs.dart:82:7)
#1      Epsg3857.latLngToOffset (package:flutter_map/src/geo/crs.dart:189:5)
#2      MapCamera.projectAtZoom (package:flutter_map/src/map/camera/camera.dart:278:11)
#3      TileRangeCalculator._calculatePixelBounds (package:flutter_map/src/layer/tile_layer/tile_range_calculator.dart:51:32)
#4      TileRangeCalculator.calculate (package:flutter_map/src/layer/tile_layer/tile_range_calculator.dart:34:20)
#5      _TileLayerState._pruneWithCurrentCamera (package:flutter_map/src/layer/tile_layer/tile_layer.dart:750:51)
#6      _TileLayerState._pruneIfAllTilesLoaded.<anonymous closure> (package:flutter_map/src/layer/tile_layer/tile_layer.dart:736:7)
#7      TileDisplay.when (package:flutter_map/src/layer/tile_layer/tile_display.dart:55:52)

device: Samsung Galaxy A52s, Galaxy A41, Galaxy Tab Active3
Flutter 3.41.7 - channel stable

I downgrade to 8.2.2

[JaffaKetchup]

Thanks for the info everyone. It looks like this a bug when we're calculating and applying camera bounds. They also shouldn't be reapplying on every build, that may be a secondary result of the bug.

I'm not around to fix this at the moment, but hopefully it can be fixed relatively soon.