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: E11 in component interface
* Undefined: E12 in component interface
* Undefined: E13 in component interface
* Undefined: E22 in component interface
* Undefined: E23 in component interface
* Undefined: E33 in component interface
* Defined: a in component interface
* Defined: bff in component interface
* Defined: bfn in component interface
* Defined: bfs in component interface
* Defined: bnn in component interface
* Defined: bns in component interface
* Defined: bss in component interface
* Undefined: Tdev11 in component equations
* Undefined: Tdev12 in component equations
* Undefined: Tdev13 in component equations
* Undefined: Tdev22 in component equations
* Undefined: Tdev23 in component equations
* Undefined: Tdev33 in component equations
* Undefined: q in component equations
The following equations couldn't be used:
* Equation in apply element with id q_calculation.
* Equation in apply element with id Tdev11_calculation.
* Equation in apply element with id Tdev22_calculation.
* Equation in apply element with id Tdev33_calculation.
* Equation in apply element with id Tdev12_calculation.
* Equation in apply element with id Tdev13_calculation.
* Equation in apply element with id Tdev23_calculation.