Flow-Launcher/Flow.Launcher

BUG: System.Net.WebException: The remote server returned an error: (666)

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#3914 opened on Aug 22, 2025

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Description

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

  • I am using the latest version of Flow Launcher.

  • I am using the prerelease version of Flow Launcher.

Problem Description

Flow Launcher got an error

Please open new issue in

  1. Upload log file: C:\Users[user]\AppData\Roaming\FlowLauncher\Logs\1.20.2\2025-08-21.txt
  2. Copy below exception message

Log File

2025-08-22.txt

Exception message

Flow Launcher version: 1.20.2 OS Version: 22631.5768 IntPtr Length: 8 x64: True

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

Date: 08/21/2025 23:50:12 Exception: System.Net.WebException: The remote server returned an error: (666) . at System.Net.HttpWebRequest.EndGetResponse(IAsyncResult asyncResult) at MS.Internal.WpfWebRequestHelper.EndGetResponse(WebRequest request, IAsyncResult ar) at System.Windows.Navigation.NavigationService.HandleWebResponse(IAsyncResult ar) at System.Windows.Navigation.NavigationService.<>c__DisplayClass102_0.b__0(Object unused) at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs) at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)

To Reproduce

N/A

Screenshots

N/A

Flow Launcher Version

1.20.2

Windows Build Number

Windows 23H2 22631.5624

Error Log


## Log File

[2025-08-22.txt](https://github.com/user-attachments/files/21932265/2025-08-22.txt)

## Exception message

Flow Launcher version: 1.20.2
OS Version: 22631.5768
IntPtr Length: 8
x64: True

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

Date: 08/21/2025 23:50:12
Exception:
System.Net.WebException: The remote server returned an error: (666) .
   at System.Net.HttpWebRequest.EndGetResponse(IAsyncResult asyncResult)
   at MS.Internal.WpfWebRequestHelper.EndGetResponse(WebRequest request, IAsyncResult ar)
   at System.Windows.Navigation.NavigationService.HandleWebResponse(IAsyncResult ar)
   at System.Windows.Navigation.NavigationService.<>c__DisplayClass102_0.<HandleWebResponseOnRightDispatcher>b__0(Object unused)
   at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
   at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)

Contributor guide

Tech stack
csharp
Domain
desktop
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-2 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
fresh
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
needs investigation
Prerequisites
C# and .NET basicsHTTP protocol understandingDebugging tools
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
25
Research direction
Investigate the NavigationService in Flow Launcher that handles HTTP requests. The stack trace shows a WebException with error code 666, which is unusual. Look at the attached log file for more context. Attempt to reproduce by simulating network requests within the app, such as checking for plugin updates or performing web searches. Examine the code in NavigationService.cs or related files to understand the request handling.