NinjaFirewall has blocked an attempt to modify a user capability by someone who does not have administrative privileges:
Blog: %1$s
Username: %2$s
meta_key: %3$s
meta_value: %4$s
User IP: %5$s
SCRIPT_FILENAME: %6$s
REQUEST_URI: %7$s
Date: %8$s
%9$s
This protection (and notification) can be turned off from NinjaFirewall "Firewall Policies" page.