This is probably a permission problem.

try chmod 745

or

chmod -vR 0755

or

restorecon -R -v directory

You need to allow the user home dir @ SELinux.

 

[root@localhost ~]# getenforce
Enforcing
[root@localhost ~]# getsebool -a | grep ftp
allow_ftpd_anon_write –> off
allow_ftpd_full_access –> off
allow_ftpd_use_cifs –> off
allow_ftpd_use_nfs –> off
ftp_home_dir –> off
ftpd_connect_db –> off
ftpd_use_passive_mode –> off
httpd_enable_ftp_server –> off
tftp_anon_write –> off
[root@localhost ~]# setsebool -P ftp_home_dir on

I wanted to change the DocumentRoot from /opt/lampp/htdocs to /home/USER/Dropbox/www.

Just change this:

 

<IfModule unixd_module>
#
# If you wish httpd to run as a different user or group, you must run
# httpd as root initially and it will switch.
#
# User/Group: The name (or #number) of the user/group to run httpd as.
# It is usually good practice to create a dedicated user and group for
# running httpd, as with most system services.
#
# User nobody
# commented out by lampp compatibility check
#Group nogroup
#Group nobody
User YOURUSERNAME
</IfModule>

 

and that:

 

DocumentRoot “/home/USER/Dropbox/www”
<Directory “/home/USER/Dropbox/www”>
#
# Possible values for the Options directive are “None”, “All”,
# or any combination of:
#   Indexes Includes FollowSymLinks SymLinksifOwnerMatch ExecCGI MultiViews
#
# Note that “MultiViews” must be named *explicitly* — “Options All”
# doesn’t give it to you.
#
# The Options directive is both complicated and important.  Please see
# http://httpd.apache.org/docs/trunk/mod/core.html#options
# for more information.
#
#Options Indexes FollowSymLinks
# XAMPP
Options Indexes FollowSymLinks ExecCGI Includes

#
# AllowOverride controls what directives may be placed in .htaccess files.
# It can be “All”, “None”, or any combination of the keywords:
#   Options FileInfo AuthConfig Limit
#
#AllowOverride None
# since XAMPP 1.4:
AllowOverride All

#
# Controls who can get stuff from this server.
#
Require all granted
</Directory>