急求，workbench中出现这个错误怎么改？

workbench中出现这个错误怎么改？
Preconditioned conjugate gradient solver error level 1.  Possibly, the  
 model is unconstrained or additional iterations may be needed.  Try     
 running setting the multiplier MULT on the EQSLV command to greater     
 than 1.0 (but less than 3.0).