I had a similar problem when I used MMM-PIR-Sensor module. Everything had been working for about 6 months then I updated something and it stoped working. I re-installed everything several times and through a process of elimination and google searches it acmes down to this particular module.

I have now got it a working again by finding the latest update from a branched version of MMM-PIR-Sensor module.

I never did find the cause.