Too many errors like this... what's the meaning?

I am getting an infinite loop of these errors in the logfile…

2018-08-14 18:20:07 ERROR (MainThread) [frontend.js.latest.201808040] https://hassxxxxxxxxx.duckdns.org/frontend_latest/df03c3bc2add9d4f4eab.chunk.js:995:510 Uncaught TypeError: t.sourceList.indexOf is not a function

How to stop and what is causing this?

Can you share your config so we can try and guess which entity might be causing this?

I think i solved this cleaning caches of my browser…