MindSphere Web Content theme could not be compiled

I am trying to upgrade a project from Mendix 8.18 to Mendix 9.15. I also followed the guide here including steps to migrate form Atlas UI 2 to Atlas UI 3. https://docs.mendix.com/refguide/moving-from-atlas-2-to-3/   I have added the Siemens MindSphere Web Content Module and it is giving theme could not be compiled error. The project is similar to Siemens MindSphere Starter Application. I have added all required modules. Directory structure and content of theme/scss files is same as in starter app. Even if I comment the variable mentioned in the error (screenshot below), it gives errors about other mindsphere scss variables. But I could not find any difference in starter app and my app’ source code. Starter app works fine and my app is giving this compilation error. Any suggestion on it? What else to check here?
1 answers

Can you please check the file /themesource/siemens_mindsphere_web_content/web/custom-variables.scss. Here should be the definition of $mindsphere-os-bar-heigt.