Hello Uday,

Thank you for posting in our community.

It seems that your project does not have the ResizeObserver installed. Having this in mind, I would suggest manually installing the missing dependency.

In case that you are creating a new Angular application from scratch, I would strongly recommend using Ignite UI CLI tool, as it will provide you with an user-friendly guided experience. The guide will lead you through all the setup options and your project will be scaffolded with a minimum effort, preventing missing dependencies issues. More information about how to use Ignite UI CLI is available here.

Please let me know if you need any further assistance regarding this matter.

Regards,
Viktor Kombov
Entry Level Software Developer
Infragistics, Inc.