[Frontend] Error on running frontend

[danhleth]

I'm currently working on a research project to develop a visualization tool for Conflict Detection and Resolution (CDR) to assist Air Traffic Controllers (ATC) (non-commercial and research on Human Machine Interface). As part of this project, I've been exploring this tool.

Issue:
While attempting to run the development server using yarn start, I encountered the following error:

But I already registered cesium and required materials.

Please help me explain the issues in this scenario. Thanks