mxRun

Is it possible for mxRun to give some help in locating an error?

i did this
mxRun(model);
and got:

Running common_path_constraint_ACE 
Error in mxRun(model) : Non-conformable matrices in Matrix Subtract.

I don't think I am using matrix subtraction, so it would be v.handy to have the error generator tag the message with where it was up to, like

"I was checking model ‘share’ when I felt I had to tell you:..."

I ran trackback() and got this, which didn't much enlighten me unfortunately.

2: .Call("callNPSOL", objective, startVals, constraints, matrices, 
       parameters, algebras, data, options, state, PACKAGE = "OpenMx")
1: mxRun(model)