If you are having trouble uploading a CSV file into ENVISION, open the file in a text editor like NotePad++ or NotePad.
Often times, file issues will show up in these programs that will not appear if you open it in Excel. Excel can sometimes hide fundamental issues with a data file that will prevent it from being read properly.
As an example, there may be extra characters populating the beginning of the file (from a conversion), or extra commas at the end of the file that will render the file too big for ENVISION to read in.
To fix this, simply delete the unneeded rows and resave the CSV file in the Text Editor program.