This happens all the time if we deploy some other modules that has javascript and not properly installed, not Odoo out of the box. Easy way is to reinstall some suspicious modules or the web module if you can. I've seen production system with this ignorable error message because the developer made mistake somewhere and can't find it and the users have to live with it. Otherwise, you need to go to Browser's developer find out the error code and try to locate it in the codebase. Sometimes, for development purposes, I put better error handling into Odoo's code to skip these error (which is due to some value is undefined and it still try to read properties). Or maybe it's right there in the sendOrerInPreparationUpdateLastChange. This name seem strange enough to be a suspect. Just like in Casablanca movie: "Round up the usual suspects"-Captain Louis Renault.