I have a clean install of ISPConfig on Debian 10. Nothing has been changed except the password for the admin account. I've added a site and DNS is working properly. I then added an FTP user to the website, however upon attempting to upload files/directories via FileZilla, I run into errors like these; Command: MKD assets Response: 550 Can't create directory: Operation not permitted What needs to be done additionally to provide FTP users with write access with ISPConfig? I was expecting it to work 'out of the box' but obviously this isn't the case. Have created an account at Gitlab to report the issue but my account is awaiting approval of some kind.
Where did you try to create that directory or upload files or directories? Directories can only be created and files and directories uploaded within the 'web' directory and within the 'private' directory of your website. I guess you tried to create a directory in / of the FTP login, which is not allowed. Go to the 'web' directory, which is the / directory when you access the site by HTTP, or go to the 'private directory, which is used for any files that shall not be accessible by http.
It worked on the second try, no changes were made. I've abandoned ISPConfig altogether now at any rate since I was also unable to receive inbound emails on a Debian 10 server. Will look for another solution that works 'out of the box' or will just install everything I need manually.
Maybe there is a firewall issue, or something like that. Feel free to open a thread for your issue. ISPConfig is great software