G0121: Matrix not positive definite [procs, line 140]
This error means that on line 140 of the file named procs, your program is passing a matrix that is not positive definite to a GAUSS function that requires a positive definite matrix.
This most commonly occurs when a program passes a matrix that is not positive definite to the GAUSS function invpd. invpd calculates the inverse of a positive definite matrix.
For more information on how to diagnose a matrix not positive definite errors see our blog, "Diagnosing a singular matrix".