FreePBX 2.8.0.1

hi
i was installed freePBX 2.8.0.1.but iam hiting the apply configuration changes
iam getting this error.
Reload failed because retrieve_conf encountered an error: 126
exit: 126
sh: /var/lib/asterisk/bin/retrieve_conf: Permission denied

1 error(s) occurred, you should view the notification log on the dashboard or main screen to check for more details.

plz help me?