Nordic ruins in Skyrim, which seem to not have been touched for thousands of years, have fresh food all over the place, be it in urns or on tables. Not to mention the player can find Septims - the currency used in the Elder Scrolls game - which shouldn't have even existed during ancient times, considering the Septim coin doesn't even exist in the Elder Scrolls Online, which takes place 2E 582, before the Septim dynasty.
Esbern, played by Max von Sydow, has a clear mismatch in voice done by an unknown voice actor during the mission when the main character has to talk to Esbern about the Elder Scrolls after he has been freed from prison.
The fence in the Ragged Flagon in Riften, Tonilia, is normally voiced by April Stewart. However, after the player gives the satchel of moon sugar to Ri'saad, the leader of the Khajiit caravans, when the player talks to Tonilia to receive acknowledgement, the specific dialogue that Tonilia says is voiced by a different person: Ellen Dubin, who is the voice actor for female commoners like Evette San and Brelas.
During the quest "Waking Nightmare", Erandur's (voiced by Keith Szarabajka) voiced is mismatched with a different voice near the end of the quest.