Warning Rich Media Migration task error - how do I proceed?

Summary:

I am trying to add Activities into a current existing Learning Course but get this error. Does anyone know how I can proceed?

Content (required):

All existing Activities and Course materials are showing successfully but this error is not allowing me to add new content or activities.

Version (include the version you are using, if applicable):

Code Snippet (add any code snippets that support your topic, if applicable):