@ry-93 said in Optimization error when multiple data feed: stdstats = False This disables the addition of observers, and the Datatrades observer is the one which cannot be pickled.

Oh thank you so much! Obvious mistake haha

@backtrader Great. Thank you for the reply. Good to have an active community. I'm still trying.

Well, you are correct! Thank you for the response.

A sample of the returned value would be needed. Else use the native Quandl support available in the last release. It has only been tested with the WIKI dataset though. See Docs - Data Feeds Reference