In case that 'Calculation left time' is not reveal..
 

When I calculate model, sometime Info massage show me the 'calculation left time'.
That is convenient for me.
But sometime Info massage dosen't show me the 'calculation left time'.
And caulculation time so long other times.

Why is not reveal 'calculation left time'?

I don't know, I never seen this problem. Maybe you can post a screenshot of this info window of the solver.

Boris