Bro: http_request

internal_func(const char* name) , in returns NULL when 'http_request'
is being passed to it.

This will happen unless your policy script defines a http_request event
handler (which you can do, for example, by using "@load http" to pull in
the usual HTTP handler). If that doesn't explain the problem you're
encountering, please send exactly how you're invoking Bro and with what
policy script.