When I created a new project in CODESYS using the "Standard Project" template and then added a Visualization, I was receiving the C0138 error during compilation. This issue persisted even with a new, completely empty project. A Quick and Effective Solution (My Method): After many attempts, I solved the problem as follows: From the File -> New Project menu, I selected the "HMI Project" template directly, instead of the "Standard Project" template. After creating the project with this template, I added...