After Serv_U security settings, the solution for 530 Not logged in, home directory does not exist appears.

Generally, this is because the parent directory of the file does not have the permission to browse. In general, we create an ftpadmin user.
File structure: d: \ wwwroot \ jb51.net
Grant the following permissions to wwwroot:

Then, assign all permissions to the ftpadmin user's jb51.net directory, and select all permissions other than full control.

In serv_u, We need to locate the jb51.net directory. You can.

Because the firewall is enabled on our server, the client (flashfxp) passive mode is required.

Detailed description:
Serv_U installation settings and 530 Not logged in, home directory does not exist Solution
The installer should use the latest version whenever possible. Avoid using the default installation directory, set the permissions of the serv-u directory, and set a complicated administrator password. Modify the banner information of serv-u, set the passive mode port range (4001-4003), and set security settings on the local server: including checking anonymous passwords, disabling anti-Timeout scheduling, intercept FTP bounce attacks and FXP. Intercept 10 minutes for users who have been connected for more than 3 times within 30 seconds. The complex password is required. The directory only uses lowercase letters. In advanced settings, the date on which the MDTM command is allowed to change the file is disabled.

Change the start user of serv-u: Create a new user in the system and set a password for the complex node, which does not belong to any group. Grant the user full control permission to the installation directory of The servu. To create an FTP root directory, you must grant the user full control permission on the directory because all ftp users upload, delete, and change files all inherit the permissions of the user; otherwise, the file cannot be operated. In addition, you need to grant the user the read permission to the parent directory above this directory. Otherwise, 530 Not logged in and home directory does not exist will appear during connection. For example, if the ftp root directory is d: \ soft \ new during the test, you must grant the read permission to the user d: \ soft. In order to safely cancel d: \ soft inherits permissions from other folders. In general, using the default system to start does not have these problems, because system generally has these permissions.