Current prelude-lml configuration has httpd.rules that deal with errors in apache logs but [format=apache] section in prelude-lml.conf deals with only common log format, not error log format. So nobody is able to parse errors since prelude-lml.conf doesn't match them. Here're the additions to prelude-lml.conf (I added additional blank lines, so remove them):

[format=apache-error]
time-format = "%a %b %d %H:%M:%S %Y" 
prefix-regex = "^\[(?P<timestamp>.{24})\] \S+ \[client (?P<hostname>\S+)\] " 
file = /var/log/httpd/error_log