Just updated to build 5023 and suddenly my project file upload setting is not working anymore and i got an error:

Failed to upload. No publishing file specified for local file D:\data\web\ff\includes\free\free.inc.php. See project properties.

Project settings:
Project - root directory: D:\data\web\ff
Publishing - Top Publishing Directory: [empty]
Mapping - Remote root directory: /www/www.ff.lv/
SFTP Account settings - root directory - /www/www.ff.lv/

Where is the problem? or is it a bug?

Before i had build 5020 and everything was working fine even when i leave Top Publishing Directory blank.
I tried to put /www/www.ff.lv/ in Top Publishing Directory because editor doesn't like empty, but then phpEd was creating such path on remote: /www/www.ff.lv/www/www.ff.lv/

I fixed this with setting "Publishing - Top Publishing Directory" to "./"

as far as I see PhpED is right because according to you it's empty:

Although it worked before, empty field is not supported anymore. If it's root directory, please enter / or particular directory publishing should work with.