BUG: unhandled external plugin's TaskSchedulerUnobservedTaskException - flow launcher crashes after new update

[youssefsyd]

Checks

• I have checked that this issue has not already been reported.

• I am using the latest version of Flow Launcher.

Problem Description

Flow Launcher version: 1.20.0
OS Version: 26100.4061
IntPtr Length: 8
x64: True

Python Path: C:\Users\dell\AppData\Roaming\FlowLauncher\Environments\Python\PythonEmbeddable-v3.11.4\pythonw.exe
Node Path:

Date: 06/03/2025 23:40:39
Exception:
System.AggregateException: A Task's exception(s) were not observed either by Waiting on the Task or accessing its Exception property. As a result, the unobserved exception was rethrown by the finalizer thread. (Object reference not set to an instance of an object.)
---> System.NullReferenceException: Object reference not set to an instance of an object.
at Flow.Launcher.Plugin.Azan.Azan.<>c.b__8_0()
at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)
--- End of stack trace from previous location ---
at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot, Thread threadPoolThread)
--- End of inner exception stack trace ---

2025-06-03.txt

To Reproduce

1. ...
2. ...
3. ...

Screenshots

No response

Flow Launcher Version

1.20.0

Windows Build Number

10.0.26100.4061

Error Log

Replace this line with the important log contents.

[Drigva]

I'm having the same issue

---

Flow Launcher version: 1.20.0
OS Version: 19044.5854
IntPtr Length: 8
x64: True

Python Path: C:\Users\Imposto é Roubo\AppData\Roaming\FlowLauncher\Environments\Python\PythonEmbeddable-v3.11.4\pythonw.exe
Node Path: C:\Users\Imposto é Roubo\AppData\Roaming\FlowLauncher\Environments\Node.js\Node-v16.18.0\node-v16.18.0-win-x64\node.exe

Date: 06/03/2025 18:02:09
Exception:
System.AggregateException: A Task's exception(s) were not observed either by Waiting on the Task or accessing its Exception property. As a result, the unobserved exception was rethrown by the finalizer thread. (Method not found: 'System.Threading.Tasks.Task Flow.Launcher.Plugin.IPublicAPI.HttpDownloadAsync(System.String, System.String, System.Threading.CancellationToken)'.)
 ---> System.MissingMethodException: Method not found: 'System.Threading.Tasks.Task Flow.Launcher.Plugin.IPublicAPI.HttpDownloadAsync(System.String, System.String, System.Threading.CancellationToken)'.
   at Flow.Launcher.Plugin.Notion.NotionDataParser.<>c__DisplayClass21_0.<<FileSave>b__0>d.MoveNext()
   at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[TStateMachine](TStateMachine& stateMachine)
   at Flow.Launcher.Plugin.Notion.NotionDataParser.<>c__DisplayClass21_0.<FileSave>b__0()
   at System.Threading.Tasks.Task`1.InnerInvoke()
   at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)
--- End of stack trace from previous location ---
   at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot, Thread threadPoolThread)
   --- End of inner exception stack trace ---

---

[procopaeus]

for me it's not even opening at all

[enoversum]

Same thing here. When I just let it restart after the update, the launcher window wouldn't appear when executing Alt + Space. When I force-close FlowLauncher and restart it manually, it appears, but throws above error messages on any search execution. Just makes you realise how dependent you became on one singular app.

[AndreyMpr]

Seemingly the same issue here.

Flow Launcher version: 1.20.0
OS Version: 19045.5854
IntPtr Length: 8
x64: True

Python Path: C:\Users\JPH108NJ12\AppData\Roaming\FlowLauncher\Environments\Python\PythonEmbeddable-v3.11.4\pythonw.exe
Node Path: 

Date: 06/04/2025 08:55:08
Exception:
System.AggregateException: A Task's exception(s) were not observed either by Waiting on the Task or accessing its Exception property. As a result, the unobserved exception was rethrown by the finalizer thread. (Traceback (most recent call last):
  File "<string>", line 9, in <module>
  File "<frozen runpy>", line 291, in run_path
  File "<frozen runpy>", line 98, in _run_module_code
  File "<frozen runpy>", line 88, in _run_code
  File "C:\Users\JPH108NJ12\AppData\Roaming\FlowLauncher\Plugins\Firefox Keyword Bookmarks-0.2.3\main.py", line 9, in <module>
    from plugin.core import plugin  # noqa: E402
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\JPH108NJ12\AppData\Roaming\FlowLauncher\Plugins\Firefox Keyword Bookmarks-0.2.3\plugin\plugin.py", line 8, in <module>
    from .bookmark import Bookmark
ImportError: attempted relative import with no known parent package
)
 ---> System.Exception: Traceback (most recent call last):
  File "<string>", line 9, in <module>
  File "<frozen runpy>", line 291, in run_path
  File "<frozen runpy>", line 98, in _run_module_code
  File "<frozen runpy>", line 88, in _run_code
  File "C:\Users\JPH108NJ12\AppData\Roaming\FlowLauncher\Plugins\Firefox Keyword Bookmarks-0.2.3\main.py", line 9, in <module>
    from plugin.core import plugin  # noqa: E402
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\JPH108NJ12\AppData\Roaming\FlowLauncher\Plugins\Firefox Keyword Bookmarks-0.2.3\plugin\plugin.py", line 8, in <module>
    from .bookmark import Bookmark
ImportError: attempted relative import with no known parent package

   at Flow.Launcher.Core.Plugin.JsonRPCPluginV2.<InitAsync>g__ReadErrorAsync|19_0() in C:\projects\flow-launcher\Flow.Launcher.Core\Plugin\JsonRPCPluginV2.cs:line 74
   --- End of inner exception stack trace ---

Logs:
2025-06-04.txt

[Jack251970]

Hi, could you please try installer here?

https://ci.appveyor.com/project/JohnTheGr8/flow-launcher/builds/52173861/artifacts

[Gowtham5006]

This same issue that I get and also I created a issue card in here.
Link: Issues created link

[enoversum]

In my case, it seemed to have been a plugin (Notion by Amin Sallah) that went tits up after the 1.20.0 update. I could read it from my error messages, maybe your case is similar. It didn't help just to disable the plugin, I had to remove it from the FL UserData→Plugins directory manually to make the error messages stop. I hope this might help some folks here.

[Jack251970]

In my case, it seemed to have been a plugin (Notion by Amin Sallah) that went tits up after the 1.20.0 update. I could read it from my error messages, maybe your case is similar. It didn't help just to disable the plugin, I had to remove it from the FL UserData→Plugins directory manually to make the error messages stop. I hope this might help some folks here.

Hi, could you please test the installer here?

https://ci.appveyor.com/project/JohnTheGr8/flow-launcher/builds/52173861/artifacts

Actually, we are trying to introduce more strict exception handling for plugins, but it is astonishing that many plugins do not follow strict coding rules. So we have to change Flow behaviour to silently handle those exception. Hopefully it can help.

[enoversum]

In my case, it seemed to have been a plugin (Notion by Amin Sallah) that went tits up after the 1.20.0 update. I could read it from my error messages, maybe your case is similar. It didn't help just to disable the plugin, I had to remove it from the FL UserData→Plugins directory manually to make the error messages stop. I hope this might help some folks here.

Hi, could you please test the installer here?

https://ci.appveyor.com/project/JohnTheGr8/flow-launcher/builds/52173861/artifacts

Actually, we are trying to introduce more strict exception handling for plugins, but it is astonishing that many plugins do not follow strict coding rules. So we have to change Flow behaviour to silently handle those exception. Hopefully it can help.

Hi Jack, since I'm using a portable version, can I use the portable one from your link above for testing? Or does it have to be the installer?

[Jack251970]

@enoversum yeah you can choose portable zip package

https://ci.appveyor.com/api/buildjobs/955j0ka0n3l53fko/artifacts/Output%2FPackages%2FFlow-Launcher-Portable.zip

[enoversum]

@enoversum yeah you can choose portable zip package

https://ci.appveyor.com/api/buildjobs/955j0ka0n3l53fko/artifacts/Output%2FPackages%2FFlow-Launcher-Portable.zip

Ah, thanks for letting me know. Unfortunately, won't be able to download today :) :

{"message":"Artifacts download limit (1024 MB/day) exceeded."}