Unable to track an entity because primary key property ‘Id’ is null – after upgrading from .Net Core 2.2 to 3.0

Error Overview

The error message “Unable to track an entity because primary key property ‘Id’ is null – after upgrading from .Net Core 2.2 to 3.0” typically indicates an issue with Entity Framework Core’s ability to manage entities after a version upgrade. This error occurs when the primary key property, often named ‘Id’, is not populated, leading to difficulties in tracking changes to the entity in the context of the application.

This issue is a common hurdle faced by developers who upgrade their applications from .Net Core 2.2 to 3.0, as changes in how Entity Framework Core handles entity tracking could lead to problems that weren’t present in the previous version.

Common Causes

Several factors may contribute to this error, including:

1. Entity Configuration Issues: Changes in Entity Framework Core’s conventions might require updates to your entity configurations.
2. Null Primary Key Values: The primary key for the entity must be assigned a value before it can be tracked.
3. Changes in Database Schema: If the database schema has changed or the migrations were not applied correctly, it can lead to discrepancies.
4. Lazy Loading Changes: Changes in how lazy loading works in .Net Core 3.0 can affect entity tracking.
5. Incorrect Context Usage: Using the wrong DbContext or creating a new context without proper configurations can lead to this error.

Solution Methods

To resolve the error “Unable to track an entity because primary key property ‘Id’ is null – after upgrading from .Net Core 2.2 to 3.0,” consider the following methods:

Method 1: Restart the Application

1. Close the Application: Ensure that your application is completely closed.
2. Restart the Application: Open the application again to reset any temporary states that may be causing the error.
3. Test the Functionality: Check if the error persists after the restart.

Method 2: Apply Latest Updates and Patches

1. Check for Updates: Look for available updates for .Net Core and Entity Framework Core.
2. Install Updates: Apply all necessary updates and patches that address known issues.
3. Rebuild the Application: After applying updates, rebuild your application to ensure all components are updated.

Method 3: Validate Entity Configurations

1. Review Entity Models: Ensure that your entity classes have the correct primary key attributes.
   “`csharp
   public class YourEntity