When you upload your LiveChat files to your server with your preferred FTP software, please make sure that all folders have not more then CHMOD 755 (except cache and files) and Files have not more then CHMOD 644 unix permissions.
Cache and files folder (also the folders inside) should have CHMOD 775. In some cases you need to set the folder permission to CHMOD 777.
Otherwise your installation process and the software cannot be started or does not work as it should! Especially when you use cPanel to upload the zip file and unpack it through the panel make sure the permissions are set correctly.