Ultima Online Artifacts in Ultima IX

Due to the very chaotic Development History of Ultima IX, which was mainly caused by the insane success of Ultima Online, things from the unconnected Ultima Online leaked into Ultima IX in Ultima Online Artifacts in Ultima IX. It is unknown if this is due to carelessness, cheapness in not wanting to create new art or simple ignorance - or willful ignoring - of the single-player lore.

Magic
A number of things were taken over from Ultima Online into the magic system.

Spell Icons
The whole spell icon system was taken over directly from Ultima Online, something that logically hadn't been in the game before the online spin-off came into being. Numerous of the spell icons are literally transplanted directly into Ultima IX, especially for the spells Heal, Light, Cure, Fireball, Telekinesis, Teleport and Tremor.

Nightshade
The sudden mutation of the mushroom Nightshade into a leaf plant (which runs contrary to all established canon) is almost certainly due to the fact that it is a leaf plant in Ultima Online. This was simply taken over without thinking about the difference in lore between the games.

Backpack Map
When looking at the rolled-up map inside the backpack, one can see that it is not the Ultima IX map. Instead, when looking closer it's obvious that it is the map of Ultima Online. Clearly, this is an art asset from the online game that had been re-used without even checking if it could create an error in continuity.

Ultima-Logo
The Ultima-logo on the box and in the manuals looks alien to followers of the single-player universe, because it is written in the font of the logo of Ultima Online, most likely being used in some way of trying to create a single brand. The title in the classic Avatar-font is only seen in the opening video in the stained glass window, as it predates Ultima Online.