I bought a system last May. Last October I started getting this error on one or two of the same sensors periodically. Now additional sensors are erroring. It's not interference because the sensors farthest away - on the basement door and the back door of my attached garage - have never had an issue and are way farther away than the ones that are having issues. I've been on the phone with support three times. They replaced the two sensors that first started having issues. Then one of those started having issues again. And it's less than 20 feet away with no walls or anything in between. I'm at a loss at this point. I'd switch to another company but don't really want to.