This error message indicates that the uploaded ZIP file does not contain all the necessary files for the selected file type.
The most common cause for this error is if the wrong file type was selected before uploading the file. Check to make sure you have selected the right file type.
Uploading an Esri Shapefile requires as a minimum the SHP, SHX and DBF files.
Uploading a MapInfo TAB file requires as a minimum the TAB and DAT files.
The Esri File Geodatabase is a complex file structure and contains many files.