WebSocket Error... the device cannot stream THIS resource

Upon opening my dashboard, for a short time a popup appears briefly:

WebSocket Error
ESP8266: the device cannot stream this resource. Maybe the resource name is not defined.

The missing resource is however not named, so one has to guess what it could be…
Would’nt it be better to improve this error message by naming the culprit?

Regards
Laszlo

@Laszlo - did you ever resolve this? I am getting the same error although nothing seems to be broken. I did switch hardware from a Sparkfun Thing to an ESP12S module running the exact same code. Like I said, everything works, but keep getting this error.