MATLAB Runtime 2024b TypeInitia​lizationEx​ception in COM-registered Windows Forms Control Library

I’m facing a blocking issue with MATLAB Runtime in a COM-registered Windows Forms Control Library inside an external application.

The issue arises when I instantiate a MWArray (or anything from the MATLAB Runtime), throwing a TypeInitializationException.

Exception:

System.TypeInitializationException
HResult=0x80131534
Message=The type initializer for 'MathWorks.MATLAB.NET.Arrays.MWNumericArray' threw an exception.
Source=MWArray
StackTrace:
at MathWorks.MATLAB.NET.Arrays.MWNumericArray..ctor(Double scalar)
at TestWindowsFormsControlLibrary.UserControl1..ctor() in ...\SandboxSolution\TestWindowsFormsControlLibrary\UserControl1.cs:line 32
    
This exception was originally thrown at this call stack:
[External Code]

Inner Exception 1:
TypeInitializationException: The type initializer for 'MathWorks.MATLAB.NET.Arrays.MWArray' threw an exception.

Inner Exception 2:
TypeInitializationException: The type initializer for 'MathWorks.MATLAB.NET.Utility.MWMCR' threw an exception.

Inner Exception 3:
Exception: Trouble initializing libraries required by .NET Assembly.

In other words:

• The issue occurs only when the control library is COM-registered and loaded in an external application (e.g., Excel).
• Without the COM registration, the same control works perfectly in a standalone Windows Forms App or WPF application.

Error Trigger Code

The exception occurs when initializing MWArray like so:

MWArray test = new MWNumericArray(0);

• If I remove this line, the COM application runs fine (no interaction with MATLAB Runtime).
• If I run the same control in a standard Windows Forms App or WPF App, it loads the MATLAB Runtime without issues.

Steps to reproduce:

1. Create a Windows Forms Control Library.
2. Set up as described in MATLAB documentation.
3. Use the MATLAB Runtime library (e.g., initialize a MWArray).
4. Build and test it within a Windows Forms App or WPF App — it works fine.
5. Register the control as a COM component and use it in an external application (e.g., Excel).
6. The TypeInitializationException is thrown.

Environment

• MATLAB Runtime version: 2024b 64-bit
• .NET Framework: 4.8.1 64-bit
• COM architecture: Only 64-bit (AnyCPU is removed)

Expected result:

I expect the MATLAB Library works in the COM-registered control as the Windows Forms Application.

Additional notes: I have only one MATLAB Runtime installed. I have it added in the PATH and it is the only entry.