[console error] Unexpected javascript error from running app

[ghjkl8000rm-tech]

Relevant console output

Uncaught Library package:dartpad_sample/main.dart was previously defined but DDC is not currently executing a hot  reload or a hot restart. Failed to define the library., error: Library package:dartpad_sample/main.dart was previously defined but DDC is not currently executing a hot  reload or a hot restart. Failed to define the library.

When did the error happen?

compileNewDDCReload
Bad state: Hot reload rejected due to:
Const class cannot remove fields: Library:'package:dartpad_sample/main.dart' Class: Student
Try performing a hot restart instead.
#0 _compile (package:dev_compiler/src/command/command.dart:381:9)

#1 _CompilerWorker.performRequest (package:dev_compiler/ddc.dart:76:18)

#2 AsyncWorkerLoop.run (package:bazel_worker/src/worker/async_worker_loop.dart:35:20)

#3 internalMain (package:dev_compiler/ddc.dart:36:5)

Your Dart code

compileNewDDCReload
Bad state: Hot reload rejected due to:
Const class cannot remove fields: Library:'package:dartpad_sample/main.dart' Class: Student
Try performing a hot restart instead.
#0      _compile (package:dev_compiler/src/command/command.dart:381:9)
<asynchronous suspension>
#1      _CompilerWorker.performRequest (package:dev_compiler/ddc.dart:76:18)
<asynchronous suspension>
#2      AsyncWorkerLoop.run (package:bazel_worker/src/worker/async_worker_loop.dart:35:20)
<asynchronous suspension>
#3      internalMain (package:dev_compiler/ddc.dart:36:5)
<asynchronous suspension>

What OS did this error occur on?

No response

What browser(s) did this error occur on?

No response

Do you have any additional information?

No response