If uploading files directly to a Canvas assignment returns an error or fails, try this alternate method for uploading files to a Canvas assignment.
1) Go to your Canvas account profile and click on the Files tab.
2) Create a new folder called File Uploads (or something similar) and upload your file(s) there. You may create a sub-folder hierarchy if desired.
3) Return to the Canvas assignment and use the "Canvas Files" option and navigate to the "File Uploads" folder that you created. Locate the file(s) that you want uploaded and add them to the assignment.
For more information on how to use your personal Canvas file storage area, please read the article below.