Repeated crash while attempting to download path as gif

[HelfireFolf]

While trying to download a path as a gif, pathplanner repeatedly gave an uncaught error "null check operator used on a null value".

To Reproduce
Steps to reproduce the behavior:

1. Go to a path and download as gif
2. go to a different path and download it as gif
3. error should appear

It should download the path as a gif but returns an error when beginning to encode the path.

• OS: Windows 11 IOT Enterprise LTSC build 26100.7623
• GUI Version: 2026.1.2
• PPLib Version: unknown
• PPLib Language: unknown

stack trace
#0 PngDecoder.decode (package:image/src/formats/png_decoder.dart:492)
#1 _TrajectoryRenderDialogState._encodeGif. (package:pathplanner/widgets/dialogs/trajectory_render_dialog.dart:311)
#2 IsolateManagerFunction.customFunction. (package:isolate_manager/src/isolate_manager_function.dart:109)
#3 _RootZone.runUnaryGuarded (dart:async/zone.dart:1778)
#4 _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:381)
#5 _DelayedData.perform (dart:async/stream_impl.dart:573)
#6 _PendingEvents.handleNext (dart:async/stream_impl.dart:678)
#7 _PendingEvents.schedule. (dart:async/stream_impl.dart:649)
#8 _microtaskLoop (dart:async/schedule_microtask.dart:40)
#9 _startMicrotaskLoop (dart:async/schedule_microtask.dart:49)
#10 _runPendingImmediateCallback (dart:isolate-patch/isolate_patch.dart:127)
#11 _RawReceivePort._handleMessage (dart:isolate-patch/isolate_patch.dart:194)