Uncaught type error

Hello my log keeps filling with the followiing error:

frontend_latest/app-6e4d53ede29a686d41a2bb0807ecd12c.js:2454:75 Uncaught TypeError: Cannot read property ‘forEach’ of undefined

Does anybody know where this comes from?

Some of your sensors are working. I had to narrow it down by disabling everything and turning things on one card at a time to figure out the culprit.

For me it was sensor.usps and sensor.fedex.