Model is underconstrained.
The following variables couldn't be defined:
 * VI in component VI
 * delta in component kinetic_parameters
 * epsilon_PI in component epsilon_PI
 * Cb in component Cb
 * Cx in component Cx
 * d/dt T in component T
 * d/dt T_ in component T_
 * d/dt VI in component VI
 * d/dt VNI in component VNI
 * d/dt Mg in component Mg
 * d/dt Mb in component Mb
 * d/dt Cc in component Cc