Error message uploading media

I've never had any issues uploading JPG/PNG, GIF and MP4 files until today. I was trying to replace some of these files that already exist in the course I'm working on, but I keep getting an error message each time I try. Unfortunately there's no message saying why the error occurred, so I have no idea how to resolve. 

Here's what I've done to resolve, to no avail:

• Signed out and back in to my Articulate account
• Checked for updates
• Run the diagnostic check
• Restarted my computer
• Tried to upload a file in a new block
• Tried to upload in a separate lesson and course

The admin of my Articulate account tested on her end and was able to upload without any issues. I have not made any changes to my account. 

Is there anything else that I may be missing to resolve this error? Of course, this has to happen while I'm finalizing a lesson!

Any help would be appreciated.