The model doesn't determine the current variables uniquely

Please help!!!

We have triple checked that all the variables and parameters are included, and can’t find the problem.
taak.mod (2.81 KB)

Your problem stems from the equation for Q+R_k(+1) which uses the value of epsilon in the denominator; but epsilon has the value of zero so that equation becomes indeterminate (put resid(1); before steady; and you will see this).