your problem is not quite clear, you might want to inckude screenshots, how you setted up etc..
am not whmcs expert but helping u to get solutions
expand on ur qs with more detail, it may help
Who is your web host ?
Make sure the permissions on folders are ch-moded correctly during your install by chance a ch mod could have not moded the perms correctly
Who is your web host ?
Make sure the permissions on folders are ch-moded correctly during your install by chance a ch mod could have not moded the perms correctly
Why don't you install it your self ?
Try disabling SSL on server configuration.