Why am I unable to attach and upload screenshots with your browser?

Hi OldManHolmes, where are you trying to upload screenshots? What is the error you're getting?

The "where" isn't really relevant. Any time I try to upload an image from my desktop using Firefox, the file is "greyed out" and cannot be selected for upload. I have no such problem with Safari, Brave, or Orion. Since I found Orion, I've given up on Firefox so it's no that big of a deal, but you were kind enough to respond & didn't want to leave you hanging. Thanks!