The URLTrigger gives severe error instead of detecting change. From trigger log:

[URLTrigger] - Poll with a URL

Inspecting Monitor a change of the content content for URL http://build.netinsight.se/autobuild/dev/acf/continuous/release/

Polling started on 2013-feb-12 12:12:12
Polling for the job dev-acf
Looking nodes where the poll can be run.
Looking for a candidate node to run the poll.
Looking for a node with no predefined label.
Trying to poll with the last built on node.

Polling on master.
[ERROR] - SEVERE - Polling error null

I think this problem started after restart (and possibly upgrade of Jenkins and URLTrigger plugin). Updating the configuration doesn't help, but if manually run once, it seems to start working again.

Attached is the config.