I have recently installed CM Partners basic mod. But whenever I get my PAartners ring my game gives me a CTD.
The only mods I currently have installed are KOTN and SI.
What could be the problem?

if i were you i'd install both the latest official and unofficial oblivion patches for starters, and i'd make sure whatever CM partners plugins you're using are loading in the right order via OBMM

also make sure you're using the SI version of CM partners just in case


EDIT: i forgot to add that you definitely need to install OBSE if you're using the latest SI version of CM partners, theres no getting around that