Error in LSODA: Code -5

I have run a control stream that runs okay following MU modeling with the mean data to establish the best structural model using NM7 with ADVAN 13 TRANS1 TOL=6. However when I attempt to run the model in a population mode with even one eta on a MU I get the following error. OCCURS DURING SEARCH FOR ETA AT INITIAL VALUE, ETA=0 ERROR IN LSODA: CODE -5 ERROR OCURRED WHILE ATTEMPTING TO OBTAIN INITIAL VALUES FOR ATOL 0PROGRAM TERMINATED BY OBJ I have seen some posts in the archives on LSODA and differential equations but nothing that seems to address my problem directly. Does anyone know of any more definitive posts or have suggestions as to how best to proceed. Thanks Andre Jackson [email protected]