syslog-ng parser using grouping-by() fails due to syntax error

Question

So, here is a quite mysterious problem regarding syslog-ng and a custom parser, using grouping-by.

Here is the parser as defined in the configurations (I left the line numbers to make it easier to identify the error message):

16 parser p_correlate_session_data {
17     grouping-by(
18         key("${source.ip}/${destination.ip}/${source.port}/${destination.port}")
19         scope("host")
20         where(match("ORIG" value("MESSAGE")))
21         trigger(match("DESTROY" value("MESSAGE")))
22         having( "${UNIXTIME}@2" ne "1" )
23         aggregate(
24             value("event.start" "${ISODATE}@2")
25             value("event.end" "${ISODATE}@1")
26             value("event.duration", "$(- ${UNIXTIME}@1 ${UNIXTIME}@2)")
27             value("MESSAGE" "Session completed; client='${source.ip}'; server='${destination.ip}'; destination_port='${destination.port}'; protocol='${network.transport}'; session_lenght='${event.duration}'\n")
28             inherit-mode("context")
29         )
30         inject-mode("pass-through")
31         # destroy events sometimes arrive later than 2 minutes, even when a client app is already closed (ssh, telnet)
32         timeout(600)
33     );
34 }; 

When I try to use this parser, I'm unable to start syslog-ng, and get the following messages in the logs:

syslog-ng[5897]: Error parsing dbparser, syntax error, unexpected ';', expecting ')' in /etc/syslog-ng/conf.d/network-ulogd2.conf>
syslog-ng[5897]: 28                  inherit-mode("context")
syslog-ng[5897]: 29              )
syslog-ng[5897]: 30              inject-mode("pass-through")
syslog-ng[5897]: 31              # destroy events sometimes arrive later than 2 minutes, even when a client app is already closed>
syslog-ng[5897]: 32              timeout(600)
syslog-ng[5897]: 33---->     );
syslog-ng[5897]: 33---->      ^
syslog-ng[5897]: 34      };
syslog-ng[5897]: 35
syslog-ng[5897]: 36      template t_network {
syslog-ng[5897]: 37          template("$(format_json --omit-empty-values --pair host.name=$HOST --pair host.hostname=$HOST --pair>
syslog-ng[5897]: 38      };

So, it seems to be that the ; character in the end of the line 33 is not supposed to be there. I reviewed the configuration many times to be sure that I had no missing () or {}.

If I comment these lines, everything works great. Syslog-ng starts and log messages from remote servers arrive as expected. I also referred to the official documentation to see if by any chance the syntax was not correct. As far as I can tell, it's not problem.

Any suggestions?