For the average player, nothing shatters the immersion of crash-landing on a hostile planet quite like a wall of red error text filling the developer console. One of the most confusing, yet increasingly common, error messages in the modern modding era (especially post- Biotech and Anomaly DLCs) is:
: The game is attempting to reference a faction that was removed from your mod list. When it can't find the faction data, it spits out an Quest Generation Failure
The primary cause of this error is almost always mod incompatibility or "mod rot."