public_html directory is writable

Checking if /home/ntwprod/domains/ntwproductions.nl/public_html/ directory is writable: Failed!

This is what I get during installation/update/advanced installation on server. Every other permission goes through.
Any suggestions how should I set it? It’s the first time I have encountered such problem (and it’s the first time I am installing revo on online server so it may be associated)?
0777 is set on public_html

Thanks, it’s appreciated.

Most likely, the owner of the script is different from the folder owner

I guess I have solved that part. Thank you AtomZap for answer.

Unfortunately, now - the website runs fine, but logging into manager is not possible. I don’t know why it points to:
Could not find action file at: E:/wamp/www/manager/controllers/default/welcome.php
as I have all file paths corrected in config.inc.php. Any ideas? Update install ran fine. Where should I look?

I am starting to get tired of that :/ MODx evolution was a lot easier to move to live server.