The kinetochore of the chromosomes
Step-by-step explanation:
What could be damaged that is hindering the spindle fibers from attaching to the chromosomes are the kinetochores of the chromosomes.
At the metaphase stage of the cell division, the chromosomes align at the equator of the cell and the spindle fibers engage each chromosome at a region known as the kinetochore.
The kinetochore is made up of complex proteins and lies around the centromere region of the chromosome. The microtubules of the spindle fibers attach to this region during the metaphase stage.
If the kinetochore is damaged, it means the spindle fiber will not be able to attach to the chromosome.