Model is unsuitably constrained (i.e. there were still some variables left to be computed, and some unusable equations left over).
At the time of the error, the following variables were found:
* Undefined: psi in component H_ATPase
* Undefined: H_int in component H_ATPase
* Undefined: H_ext in component H_ATPase
* Undefined: mu_H in component H_ATPase
* Defined: mu_0 in component H_ATPase
* Defined: xi in component H_ATPase
* Defined: F in component H_ATPase
* Defined: R in component H_ATPase
* Defined: T in component H_ATPase
* Defined: z in component H_ATPase
* Defined: J_Vtype_H_Max in component H_ATPase
* Undefined: J_Vtype_H in component H_ATPase
The following equations couldn't be used:
* Equation in apply element with id electrochemical_potential_difference_calculation.
* Equation in apply element with id H_flux.