When I tried to import my data with format zip into ArcGIS Online it failed with an error message of:

> Can not import this shapefile

For details of my data as follow:

 1. Has 600 records
 2. In mydata.zip contain the .shp,.shx,.dbf,.prj
 3. When I tried to decrease mydata become 73 records and save to shapefile, then I have success importing the shapefile to ArcGIS Online.
 4. I have a student license from my university

I use QGIS just for create a layer point geometries and save to shapefile. I haven't found a solution yet.