Thanks for reporting this. And my first advice would be to uninstall the game and reinstall it (backing up your save files in case). If that doesn't work, then it is possibly a bug. In that case, could you explain a bit more? There are several occasions when you can visit the Riverside before entering the city. Which exact quest were you on or even better, what were the hints in the crystal ball (for the Main Story and Myrtle's quest) when this happened.