File picker error - 'File does not exist' on XFCE
When attempting to send a file via HTTP Upload, sometimes the file selection fails. When you select a file, you get a "File does not exist" error dialog. Closing the file picker and re-trying (with the same file!) fixes it.
I usually only send single files, so that's when I've usually encountered it. Haven't tried with multiple files.
I'll post debug log output when I encounter it again. If I remember correctly, the log contained a GTK error of some sort.