### Author:  [@Starman](https://discourse.glfw.org/u/Starman)
#### Post date: [June 22, 2024, 11:09am UTC](https://discourse.glfw.org/t/wgl-failed-to-clear-current-context-the-handle-is-invalid/2663/1 "2024-06-22T11:09:05Z")
I’m using glfw-net, a NuGet package that lets me use glfw in c#
When I run `glfw.Terminate()` this error is thrown.
This is the full code:
```auto
using GLFW;
using OpenGL;
namespace Starlight
{
class Program
{
private static List ents = [];
static void Main(string[] args)
{
if (!Glfw.Init())
{
String msg;
throw new System.Exception($"GLFW STARTUP ERROR {Glfw.GetError(out msg)}: {msg}");
}
Glfw.WindowHint(Hint.ContextVersionMajor, 3);
Glfw.WindowHint(Hint.ContextVersionMinor, 3);
Glfw.WindowHint(Hint.OpenglProfile, Profile.Core);
var window = Glfw.CreateWindow(800, 600, "Starlight", GLFW.Monitor.None, Window.None);
if (window == Window.None)
{
String msg;
throw new System.Exception($"GLFW WINDOW CREATION ERROR {Glfw.GetError(out msg)}: {msg}");
}
Glfw.MakeContextCurrent(window);
Gl.Viewport(0, 0, 800, 600);
Glfw.SetFramebufferSizeCallback(window, WinManager.frameSizeChange);
while (!Glfw.WindowShouldClose(window))
{
Entity.MegaUpdate(ents);
Glfw.SwapBuffers(window);
Glfw.PollEvents();
}
try
{
Glfw.Terminate();
}
catch (GLFW.Exception e)
{
String msg;
Console.Error.WriteLine($"ERROR: {e.Message}, GLFW ERROR CODE: {Glfw.GetError(out msg)}: {msg}");
}
}
}
}
```
---
### Author:  [@Starman](https://discourse.glfw.org/u/Starman)
#### Post date: [June 22, 2024, 11:14am UTC](https://discourse.glfw.org/t/wgl-failed-to-clear-current-context-the-handle-is-invalid/2663/2 "2024-06-22T11:14:31Z")
After a bit of testing the line that causes it is `Gl.Viewport(0, 0, 800, 600);`
---
### Author:  [@dougbinks](https://discourse.glfw.org/u/dougbinks)
#### Post date: [June 22, 2024, 2:37pm UTC](https://discourse.glfw.org/t/wgl-failed-to-clear-current-context-the-handle-is-invalid/2663/3 "2024-06-22T14:37:54Z")
The error likely comes from the line `Glfw.MakeContextCurrent(window);` as this is the one which sets the context. However the error `Failed to clear current context` is usually only valid if `NULL` window parameter is passed (in C, not sure about the C# implementation).
I would check with the developer of the C# package and also check whether the `window` variable is valid (you check against `Window.None` but I’m not sure if this is the correct check as I don’t know the C# GLFW library.
---
### Author:  [@Starman](https://discourse.glfw.org/u/Starman)
#### Post date: [June 22, 2024, 6:42pm UTC](https://discourse.glfw.org/t/wgl-failed-to-clear-current-context-the-handle-is-invalid/2663/4 "2024-06-22T18:42:29Z")
I see that also I cannot change the clearcolor, this supports your claim, thanks, I will take a look
---
### Author:  [@Starman](https://discourse.glfw.org/u/Starman)
#### Post date: [June 22, 2024, 6:44pm UTC](https://discourse.glfw.org/t/wgl-failed-to-clear-current-context-the-handle-is-invalid/2663/5 "2024-06-22T18:44:19Z")
Window.None is a fancy way to say null, the description says so