need help understanding error=-4 from pardiso

I am calling pardiso with mtype=11 (real nonsymmetric).

I first call it with phase=11, iparm(1)=0, and the result is error=0.  So all is good.

I then call it with phase=22, and error=0.  So all is still good.

I then call it multiple times with phase=33 with different rhs's.  The first two calls return error=0, but the third call returns error=-4.  What does this mean?  Does -4 mean I have a bug somewhere, or can -4 be generated by something it doesn't like about the rhs?  The rhs for the third call looks normal to me (i.e. no outlier elements).