I had the problem where I could not upload anything. I got the error Is its parent directory writable by the server? I found this topic: Can't upload images in any of my local projects but there was not solution mentioned there.
I found my solution!
In Wordpress > Settings > Media I had a custom url from my live site. There are two field: 1) Store uploads in this folder, 2) Full URL path to files.
Field 1 should be wp-content/uploads and field 2 should be empty.
If you don’t see these field, that means you already have the default settings and this is not your solution. Check permissions.
