Crash - ReferenceError: device is not defined

[rawbar]

All was running great with 2 KP115s. Then I added 2 more. Things run fine for maybe 60 seconds, I can see all 4 reporting and showing stats, then the app crashes with the below error. Any ideas?

H:\tplink-monitor-win>tplink-monitor-win.exe
Logger config file: "logger-config.json"
Log directory path: "."
Found device with energy monitor support: Ryan Desktop [8006FAF9A79A64DC90337837482CDF681DB576AF]
Logging started for Ryan Desktop [8006FAF9A79A64DC90337837482CDF681DB576AF] every 60 seconds
Found device with energy monitor support: Rig 1B [8006F8565B17D7330E094C0203BDCEFA1DB5109D]
Logging started for Rig 1B [8006F8565B17D7330E094C0203BDCEFA1DB5109D] every 60 seconds
Found device with energy monitor support: Rob Desktop [800680CED259974A996F4608A4B4F8D41DB65B75]
Logging started for Rob Desktop [800680CED259974A996F4608A4B4F8D41DB65B75] every 60 seconds
Found device with energy monitor support: Rig 1A ZTX [80060F27A8A2EE23AF298032717594B61DB6524B]
Logging started for Rig 1A ZTX [80060F27A8A2EE23AF298032717594B61DB6524B] every 60 seconds
GET /80060F27A8A2EE23AF298032717594B61DB6524B 200 20.025 ms - 12112
GET /stylesheets/style.css 304 0.675 ms - -
GET /javascripts/dash.js 304 0.407 ms - -
GET /favicon.ico 200 5.743 ms - 12000
fs.js:511
callback(null, buffer);
^

ReferenceError: device is not defined
at writeLog (C:\snapshot\tplink-energy-monitor\services\data-logger.js:0:0)
at device.emeter.getRealtime.then.getLogEntries (C:\snapshot\tplink-energy-monitor\services\data-logger.js:0:0)
at fs.access.fs.readFile (C:\snapshot\tplink-energy-monitor\services\data-logger.js:0:0)
at FSReqWrap.readFileAfterClose [as oncomplete] (fs.js:511:3)

H:\tplink-monitor-win>