Model is underconstrained.
The following variables couldn't be defined:
 * X in component X
 * Ctot in component C
 * V1 in component V1
 * M_ in component M
 * V3 in component V3
 * X_ in component X
 * Ytot in component Y
 * BP in component BP
 * d/dt C in component C
 * d/dt M in component M
 * d/dt X in component X
 * d/dt Y in component Y
 * d/dt Z in component Z