Hello @466824 and welcome to the Canvas Community! Thanks for reaching out and your question.
I would suggest you contact your instructor on the matter and contact Canvas support:How do I get help with Canvas as a student? , so that they can have a better look into your specific course and file(s) your wanting to upload. They may be able to see something from their end we can not.you
I hope this helps and let us know if you need further assistance or have additional questions. Thanks!