# ObjectDisposedException: Cannot access a disposed context instance

**Code:** `Cannot access a disposed context instance` · **Category:** .NET · **Seen on:** .NET

Code used a DbContext after its scope ended — usually async void, fire-and-forget tasks, or capturing a scoped context in a singleton/background thread.

## Meaning

The request scope disposes the context when the request finishes. Work continuing after that (unawaited tasks, events, background threads) fails.

## Common causes

- async void or un-awaited Task using the context
- Context captured by a singleton/hosted service
- Lazy-loading navigation after the request ended

## Quick fix

1. Await all work within the request
2. Use IServiceScopeFactory/IDbContextFactory in background work
3. Materialise data before returning

## Detailed fix by platform

### C#

1. 

```csharp
using var scope = scopeFactory.CreateScope();
var db = scope.ServiceProvider.GetRequiredService<AppDb>();
await db.SaveChangesAsync();
```


## How to diagnose

1. **Timing** — After the request?
2. **Lifetime** — Who holds the context?

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Source: [WhatIsMyError](https://whatismyerror.com/errors/dotnet/cannot-access-disposed-context)