This probably applies for all platforms but the moment you hit a point in the main quest where

SPOILER ALERT! DO NOT READ FURTHER IF YOU DON'T WANT AN EARLY POINT IN THE MQ TO BE SPOILED FOR YOU!

Delphine puts on her adventurers armor to travel with you, you can no longer ask her for a room. This sadly makes the inn in Riverwood completely useless.

Please fix this!