After upgrading from 1.30.4, to 1.32.x from the iconnor ppa, ZM refuses to run.
I'm not certain whether it's the fault of ZM, or the install scripts being run by the ppa, but the fix is easy...
After the upgrade, simply sudo chown -R root:www-data /etc/zm/*
After that, ONVIF probing, and the monitors that existed prior to the upgrade, will all work.
Hope this helps someone who just had an "OHCRAP!" moment, as I just did.
-dws