I had the same problem, I solved changing the ports.
-> Clicked button Config front of Apache.
1) Select Apache (httpd.conf)
2) searched for this line: Listen 80
3) changed for this: Listen 8081
4) saved file
-> Click Config button front of Apache.
1) Select Apache (httpd-ssl.conf)
2) searched for this line: Listen 443
3) changed for this: Listen 444
4) saved file
I can run xammp from port 8081
http://localhost:8081/
You have to give port number you gave to enter the localhost
Hope this helps you to understand what is happening.