If you are in any of the drawers in your File Cabinet and you see the button Choose File and your file doesn't seem to upload once you choose that file here are some handy steps to correct that.
Next to your URL you will now see an i with a circle around it.
Click that Icon and a menu with expand. Look for Flash.
Next to Flash set the option that says "Ask (default)" to "Always Allow"
Reload your page and then upload your file.