I get codes back in the day when storage for a whole book was costly, but that isn't the case anymore. Just tell us the error, show us the pointers, and then tell us what typical fixes are instead of expecting us to go to the internet for a solution.
As developers, we also have to be used to a lot of completely unhelpful errors. Yeah, couldn't connect to the DB, sure... oh, but actually because my code ate all of memory, why didn't you say that in the first place?
Software just kept the tradition of error codes, since that meant you could also sell that juicy documentation (localized into whatever language you wanted) to the user as well. I suspect it also a localization issue because OracleDB would never return the table/column in the error message, so as to be easier to translate.
The modal dialog breaks UX spectacularly.
Even logs should have messages that actually are intuitive to follow.
Or cause the user had filled in part two of a task but not part one and then tried to continue with parts of the task that where dependent on filling in part one.
Or the user tried to synchronize orders from the erp system but the erp system would not return any orders.