Armed is not used by Reactor for any purpose. It is just a carry-along from the fact that a ReactorSensor is implemented to look like a security sensor to Vera (and security sensors have armed/disarmed as a feature). Others have not reported any issue related to armed state of ReactorSensors, and I have also attempted to duplicate your issue in my test environments (various firmware on two Vera Pluses, a Vera3 and a Vera Lite) and have been unable to do so. I have a few things I’d like you to try, which I will PM to you shortly.
Hi - new to Reactor and ran into an issue that I’ve solved but it did throw me for a loop - if I “Arm” a Reactor Sensor it will not successfully trip - trying to trip it manually or through conditions will result in a “Device Not Ready” error. Running your Logic Summary page during that time will raise a 503 error - Service Unavailable - and my last configuration change will be lost. If the Sensor is “Disarmed” but “Enabled”, it works correctly. It will even throw that error on a new Sensor with nothing but the comment in the conditions list - create a new sensor, push “Trip” button and I get the error. I didn’t want to post something new if I missed a note on this somewhere so just replied to the closest thing I saw.
Armed is not used by Reactor for any purpose. It is just a carry-along from the fact that a ReactorSensor is implemented to look like a security sensor to Vera (and security sensors have armed/disarmed as a feature). Others have not reported any issue related to armed state of ReactorSensors, and I have also attempted to duplicate your issue in my test environments (various firmware on two Vera Pluses, a Vera3 and a Vera Lite) and have been unable to do so. I have a few things I’d like you to try, which I will PM to you shortly.
Closing the loop (Luup 
) on this… @wmichael3 has security cameras that are set up to take pictures when an armed sensor is tripped. So when his RS tripped, one of his cameras was trying to capture, and causing a crash. Removing the camera from the configuration seems to have stabilized his system.
But, neither he nor I have any idea where that camera behavior is configured (I don’t use cameras with my Veras). So if anyone reading knows, please chime in and help with some configuration guidance. It seems reasonable that he should be able to pick and choose which sensors cause captures. We found it.