I’m sorting through old jpgs. If I make an adjustment and want to Export to Disk as a jpg I get the options to either Overwrite / Use unique names / Cancel. When I choose to Overwrite I get the message that the source image cannot be overwritten.
Why am I given the choice if it’s not possible?
Thanks for everyone’s reply. Got it. 
You receive that message any time the export file already exists. Usually it’s because you’ve exported edits previously and now you’ve made changes and want to re-export. However, I’m wondering if that’s the case for you.
I see two possibilities: the file permissions in the OS don’t allow you to overwrite the file, or the export filename is the same as the name of the file you’re working on in PhotoLab, which goes against how PhotoLab works.
The “problem” for you is: PL doesn’t overwrite the original file. In your case it’s the jpg-file. So you aren’t allowed to overwrite it.
Why you get the choise? I don’t know, but I think it’s no problem if you understand the reason;-)
New to me too.
But normally one has the Save option, write back with the same name and in the same directory, and Save As, change the name and/or directory.
Export is by definition to change the name or directory in a new file.
I write the jpg files in a sub directory jpg. Opening a jpg and exporting it again results in a new sub directory jpg:…jpg\jpg. When reopening the same jpg again and exporting it as a jpg doesn’t give that blockage. The original isn’t overwritten but the former export is.
By the way, keep your original always. Gone is gone.
George
PhotoLab is a non-destructive editor. There is no save feature, only export. Unlike a pixel editor you cannot overwrite the file you’re editing. Some people are under the impression this only relates to the editing of raw files but, by design, it relates to any file type being edited in PhotoLab.
Mark
That’s what I wrote. Relative to the original file:
Save: overwrite the original with the same extension.
Save as: one may change the destination, file name and/or extension.
Export: one has to change one of them.
A raw extension can never be a new extension.
There is no Save or Save As option in PL. And I assume in any other raw editor.
George
Yes … Hence, I reckon you’re probably editing (with PL) a JPG file - then attempting to export the result, as a JPG, into the same folder as the original JPG file
… That’s not doable.