My newly installed server gives 500 internal error

[megaster55]

I am using apache, litespeed and php 5.3 in my newly installed cwp but when I add a site and send a php script it gives a 500 internal error. When I run "user accounts> Fix Permissions" it is fixed but when I add a new domain the same thing happens again. Nothing like this happened on the server I installed before, both were taken from OVH server.  I tried many times the same

[rcschaff]

tail -n 50 /usr/local/apache/domlogs/{domain}.error.log