при установке соц сети sngine-v2_5_5-nulled
выдает ошибка:

Internal Server Error

The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator, webmaster@royalgram.ru and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

Apache/2.2.22 (Debian) Server at royalgram.ru Port 80
как исправить?

.htaccess смотри

+

в большинстве случаев оно так и бывает