Error encountered "The learning resource is not valid. An Activity node is required for content used in Microsoft Learning Components"

We developed a quiz using Adobe Captivate 8. The quiz is published as HTML5 and SCORM-compliance.

It contains video and audio which were captured using Captivate 8's recording feature.

We published the quiz into SharePoint Learning Kit - a sharing platform.

However, we encounter an error "The learning resource is not valid. An Activity node is required for content used in Microsoft Learning Components.".

Grateful for advice pl. Thank you.