-> open terminal.
-> login as root
-> go to /opt/lampp/etc/extra
-> open httpd-xampp.conf file.
Now insert the following code at the end of the file,
<LocationMatch "^/(?i
?:xampp|security|licenses|phpmyadmin|webalizer|server-status|server-info))">
AllowOverride AuthConfig Limit
Require all granted
# Require local
#Require all
ErrorDocument 403 /error/XAMPP_FORBIDDEN.html.var
</LocationMatch>