The root cause of this error is that the `dynamic` keyword requires additional references to be included in the project. These references are typically found in the Microsoft.CSharp and System.Core assemblies.Another potential cause is that the `System.RuntimeBinder` namespace, which is required for

How do I fix: Importing the Required Namespace?

Step 1: Open the code file containing the problematic line of code.Step 2: Add a using statement at the top of the file for System.RuntimeBinder, like so: `using Microsoft.CSharp.RuntimeBinder;`Step 3: Alternatively, you can also import the namespace directly in the problematic line of code, like so

Coding⏱️ 3 min read📅 2026-06-03

How to Fix: One or more types required to compile a dynamic expression cannot be found. Are you missing references to Microsoft.CSharp.dll and System.Core.dll?

Q: How do I fix: 🔧 Proven Troubleshooting Steps Including Required References?

Step 1: Open the Project Properties by right-clicking on the project in Visual Studio and selecting 'Properties'.Step 2: In the Project Settings window, navigate to the 'References' tab.Step 3: Check that Microsoft.CSharp and System.Core are listed as referenced assemblies.Step 4: If not, add them b

Missing references to Microsoft.CSharp.dll and System.Core.dll for dynamic expression compilation.

Quick Answer: Add a reference to Microsoft.CSharp.RuntimeBinder NuGet package or use the full .NET Framework version.

📋 Table of Contents

⚠️ Common Causes
🔧 Proven Troubleshooting Steps
✨ Wrapping Up

The error 'One or more types required to compile a dynamic expression cannot be found. Are you missing references to Microsoft.CSharp.dll and System.Core.dll?' occurs when trying to use the `dynamic` keyword in C#.

This error is frustrating because it prevents the code from compiling, making it difficult to complete the task at hand.

⚠️ Common Causes

The root cause of this error is that the `dynamic` keyword requires additional references to be included in the project. These references are typically found in the Microsoft.CSharp and System.Core assemblies.
Another potential cause is that the `System.RuntimeBinder` namespace, which is required for dynamic typing, has not been imported correctly.

🔧 Proven Troubleshooting Steps

Including Required References

Step 1: Open the Project Properties by right-clicking on the project in Visual Studio and selecting 'Properties'.
Step 2: In the Project Settings window, navigate to the 'References' tab.
Step 3: Check that Microsoft.CSharp and System.Core are listed as referenced assemblies.
Step 4: If not, add them by clicking on the 'Add Reference...' button and browsing to their locations.

Importing the Required Namespace

Step 1: Open the code file containing the problematic line of code.
Step 2: Add a using statement at the top of the file for System.RuntimeBinder, like so: `using Microsoft.CSharp.RuntimeBinder;`
Step 3: Alternatively, you can also import the namespace directly in the problematic line of code, like so: `System.RuntimeBinder.Binder binder = new Binder();`

✨ Wrapping Up

By following these steps, you should be able to resolve the 'One or more types required to compile a dynamic expression cannot be found' error and complete your C# project successfully.

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