Hex Editor displays unnecessary notification when a previously-opened file is deleted

[joyceerhl]

1. Open a file in the hex editor
2. Close the hex editor
3. Delete the file
4. 🐛 get this warning from the hex editor:

[cyjohnson-ss]

Confirmed

[AaronRidoutAE]

There is another two parts to this issue that I see.

1. Even though the file is closed, this still pops up and the 'Close Editor' button closes the current window - not the offending one (which in my case is already closed!). Please only close the offending window, not the current one!
2. The pop up does not say which file it is warning about - I have many files open and one of them is transitory (being built in my case). Please add the filename to the pop-up!