zmfilter.pl kept dying.

[magicloud]

Just out of nowhere, my zoneminder did not alarm any more.
Checking the log, I see this in zmdc.log. What happened?

09/23/2011 18:37:24.040599 zmdc[22750].INF ['zmfilter.pl' starting at 11/09/23 18:37:24, pid = 22810]
09/23/2011 18:37:29.360109 zmdc[22750].ERR ['zmfilter.pl ' exited abnormally, exit status 9]

And following is when I `sudo perl -TW /usr/bin/zmfilter.pl`

Use of uninitialized value in join or string at /usr/lib/perl5/DBI.pm line 1690.
Use of uninitialized value in join or string at /usr/lib/perl5/DBI.pm line 1690.
Can't use an undefined value as an ARRAY reference at /usr/bin/zmfilter.pl line 274.

[magicloud]

I get it. Weird.
Why cannot zmfilter.pl work with NO CRITERIAS?