This is a known issue with an prototype polution caused by other nodes.
See this thread: 🎉 Node-RED 2.0.0-beta.1 Released - #84 by Botched1
Do you have any of these nodes installed...
- node-red-contrib-deconz-test-zehir - issue raised - fixed in v1.3.3
- node-red-contrib-defaro - issue raised
- node-red-contrib-zigbee2mqtt - issue raised - fixed in v0.6.9
- node-red-contrib-wirenboard - issue raised - fixed in v3.5.1
- node-red-contrib-deconz - Issue raised - fixed in v1.3.3
- node-red-contrib-zway - Issue raised - fixed in v1.0.0
- node-red-contrib-spruthub - Issue raised - fixed in v1.0.4
See here for workaround...
