Canvas allows instructors to export and import the gradebook so that changes can be made in Excel. Unfortunately, both Mac and PC users have to avoid corrupting the exported file. Excel treats the exported file differently for both PCs and Macs, and both operating systems have separate errors that can occur resulting in an "Invalid CSV File" failure:

 Using a Mac to make grade changes in Excel

While exporting the gradebook and opening it in Excel on a Mac, you may notice some strange characters that appear in the "Student" cell (A1). They should look somewhat like the "ϊ≫¿Students" characters indicated in the red box in the image below:

Removing these extra characters will allow the file to be successfully imported back into the gradebook. After making changes and deleting these characters, it is important to click File > Save As, and ensure that the file is being saved in a Comma Separated Values (.csv) format. After saving the file as a .csv, Excel will pop-up a prompt asking if it is okay to save the file in this format. Clicking continue will allow the file to be imported back into your course site. 

Using a PC to make grade changes in Excel

When exporting the gradebook and opening it in Excel on a PC, it is vital that you do NOT click the floppy-disk icon before clicking File > Save As > CSV (Comma Delimited).

Running Excel on a PC automatically reverts to saving your exported gradebook file as a Unicode Text File. This file format will throw off your data, and you will need to export the gradebook again and start from scratch in order to import your grade changes successfully. 

It is very important that you do not click Save without designating the file format. The error shown in the image above does not appear until after you close and reopen your gradebook file, so it is easy to be under the impression that everything is working as intended. Clicking Save As will allow you to choose the correct file format, CSV (Comma Delimited):

After selecting CSV (Comma Delimited), Excel will prompt you to approve the format change. Selecting yes and closing the program will allow the file to import successfully.