This version can only be installed if no older versions (before November 2025) of several add-ons are installed:

• No old setup add-ons: CODESYS Communication, Visualization, Ethernet IP, Application Composer.
• No old optional add-ons: CODESYS ControlElement Library, IIoT Libraries, OPC UA Client API.
• No CODESYS OPC UA Pub/Sub before 1.4.0.0 (release not yet scheduled).

Reason: It cuts dependencies on CAA libraries. This introduces an incompatibility where user-defined data types are used in Element Collections (they now need to implement MBM.IDisposable).

Additionally it includes fixes for multi casting (Net Base Services) and online change (Element Collections),
and provides an updated library project template.

The package is available via the CODESYS Installer.
You can purchase the corresponding single-device license in the “Application-Based Licenses” category of the CODESYS Store.

Application-based licenses

This version prepares the transition to version 5.0: It provides unbound-placeholder resolution for the Memory Block Manager library of CODESYS. This allows for add-ons and for projects that can safely switch between Base Libraries 4.0.1 and 5.x.

This new add-on contains six established libraries that simplify and support the development of other libraries and applications (setup modularization II): data structures, asychronous jobs, IP communication, etc.