End of LCC Compiler support in MATLAB/Simulink

I have recently upgraded to MATLAB/Simulink R2023a or later. I encounter the following errors when I try to run or update my Simulink model, or use features such as fixed-point conversion:

Unable to determine MEX compiler or selected MEX compiler is not supported. Use 'mex -setup' to configure one.
Unable to determine MEX compiler: use 'mex -setup' to configure your system. Note that the LCC compiler is deprecated and no longer available.

When I try to run my model with model references in Accelerator or Rapid Accelerator mode or build my model using Simulink Coder or Embedded Coder, I get the following yellow alert in my model:

Model uses LCC compiler for code compilation. LCC compiler will be removed in a future release. Consider using a different compiler.
For information about supported compilers, see https://www.mathworks.com/support/requirements/supported-compilers.html.
Using this page or the Add-On Explorer at MATLAB Support for MinGW-w64 C/C++ Compiler, you can download the MinGW compiler.

Before R2023a, I could do the same MATLAB/Simulink workflows without installing an additional compiler.

Answer 1

[MathWorks Support Team]

The LCC compiler is no longer supported in MATLAB and Simulink. Please install a supported compiler, such as MinGW-w64 or Microsoft® Visual C++.

For more details, see the following:

Historical Use of LCC Compiler

Many MathWorks product features require a supported third-party compiler. The MathWorks Installer also notifies you of these compiler requirements at the end of the installation.

In previous releases, the LCC compiler was supported as a fallback option for the products Simulink, MATLAB Coder, SimBiology, Fixed-Point Designer, HDL Coder, HDL Verifier, Stateflow, Simulink Coder, and Embedded Coder.

This meant that if MATLAB didn’t find a supported compiler, it could fall back on the LCC compiler, allowing users to work with certain MathWorks products without installing a third-party compiler.

LCC Compiler Deprecation

In the R2023a release, MathWorks announced the deprecation and future removal of the LCC compiler (see R2023a Simulink release notes). As a result, users may encounter the above-mentioned errors or warnings about the LCC compiler or toolchain in releases R2023a or later. The official end of LCC support for Simulink and related products was announced in R2024a (see R2024a Simulink release notes).

Note that the LCC compiler had been discouraged for many years. The following statement can be found in our Supported Compilers PDF documentation since R2020b: "The lcc-win64 compiler is no longer supported and will be removed in a future release of MATLAB and Simulink. MathWorks recommends you install one of the other compilers listed on this page when using these products."

Recommended Action for Users

Always install a supported compiler when using MathWorks products or product features that require one. For Windows, the MinGW-w64 compiler is recommended and can be accessed via the MATLAB Add-On Explorer or File Exchange:

MATLAB Support for MinGW-w64 C/C++ Compiler

For rollouts to many systems and offline installations, use our offline support package installer:

How do I download and install a support package on an offline machine?