create-react-app: Uncaught TypeError: inst.setState.bind is not a function

I’m getting this error when running npm start, however it goes away when i do npm run build and serve that. Any ideas? I’m not exactly sure what’s causing it, it’s related to setState though, from a result of a UI interaction callback. It doesn’t seem to cause problems… (famous last words).

Uncaught TypeError: inst.setState.bind is not a function
getData @ backend.js:8511
receiveComponent @ backend.js:8317
obj.(anonymous function) @ backend.js:8387
updateChildren @ ReactChildReconciler.js:110
_reconcilerUpdateChildren @ ReactMultiChild.js:210
_updateChildren @ ReactMultiChild.js:314
updateChildren @ ReactMultiChild.js:301
_updateDOMChildren @ ReactDOMComponent.js:941
updateComponent @ ReactDOMComponent.js:759
receiveComponent @ ReactDOMComponent.js:717
receiveComponent @ ReactReconciler.js:126
obj.(anonymous function) @ backend.js:8386
updateChildren @ ReactChildReconciler.js:110
_reconcilerUpdateChildren @ ReactMultiChild.js:210
_updateChildren @ ReactMultiChild.js:314
updateChildren @ ReactMultiChild.js:301
_updateDOMChildren @ ReactDOMComponent.js:941
updateComponent @ ReactDOMComponent.js:759
receiveComponent @ ReactDOMComponent.js:717
receiveComponent @ ReactReconciler.js:126
obj.(anonymous function) @ backend.js:8386
_updateRenderedComponent @ ReactCompositeComponent.js:761
_performComponentUpdate @ ReactCompositeComponent.js:739
updateComponent @ ReactCompositeComponent.js:658
receiveComponent @ ReactCompositeComponent.js:552
receiveComponent @ ReactReconciler.js:126
obj.(anonymous function) @ backend.js:8386
_updateRenderedComponent @ ReactCompositeComponent.js:761
_performComponentUpdate @ ReactCompositeComponent.js:739
updateComponent @ ReactCompositeComponent.js:658
receiveComponent @ ReactCompositeComponent.js:552
receiveComponent @ ReactReconciler.js:126
obj.(anonymous function) @ backend.js:8386
_updateRenderedComponent @ ReactCompositeComponent.js:761
_performComponentUpdate @ ReactCompositeComponent.js:739
updateComponent @ ReactCompositeComponent.js:658
performUpdateIfNecessary @ ReactCompositeComponent.js:566
performUpdateIfNecessary @ ReactReconciler.js:158
obj.(anonymous function) @ backend.js:8386
runBatchedUpdates @ ReactUpdates.js:151
perform @ Transaction.js:138
perform @ Transaction.js:138
perform @ ReactUpdates.js:90
flushBatchedUpdates @ ReactUpdates.js:173
closeAll @ Transaction.js:204
perform @ Transaction.js:151
batchedUpdates @ ReactDefaultBatchingStrategy.js:63
batchedUpdates @ ReactUpdates.js:98
dispatchEvent @ ReactEventListener.js:150