Invalid Solution File

[VisionSPI]

When importing Error:
The solution file is invalid. The compressed file must contain the following files at its root: solution.xml, customizations.xml, and [Content_Types].xml. Customization files exported from previous versions of Microsoft Dynamics 365 are not supported.

[JaredSRairdon]

Hi there

You are most likely trying to import the source code zip, instead of the solution file.

Download either the Managed or Unmanaged release from here (expand the 'assets' dropdown), then try importing again
https://github.com/scottdurow/power-drag-drop/releases