Quick Answer

Handle protected memory access.

Understanding the Issue

This exception occurs when attempting to access invalid or protected memory, often in interop scenarios.

The Problem

This code demonstrates the issue:

Csharp Error 
[DllImport("native.dll")]
static extern void UnsafeMethod();
UnsafeMethod(); // May throw

The Solution

Here's the corrected code:

Csharp Fixed 
// Add proper marshaling
[DllImport("native.dll", CharSet = CharSet.Unicode)]
static extern void SaferMethod(string input);

// Use SafeHandle
[DllImport("native.dll")]
static extern SafeHandle CreateResource();

// 32-bit compatibility
// Some older libraries require x86

// Memory diagnostics
// Use tools like WinDbg to diagnose corruption

// Managed alternatives
// Prefer pure C# solutions when possible

Key Takeaways

Validate native interop calls thoroughly and prefer managed alternatives.