Check the software versions first...

If you ever find yourself debugging stuff locally, on staging, production etc.......please please please check if the software versions are correct. You wouldn't believe how many (even experienced) people have been bitten by these obvious errors.

After hours of debugging, you are still wondering how come that API doesn't work?? Then an colleague comes along and says: "Dude you're using a way older version, we're on the 3.X.X version now"  :)

ahhhhh software development....fun times.....