求LINGO大神,程序出现too many inequality or equality relations

求LINGO大神,程序出现too many inequality or equality relations
model:
max=0.9*x1+1.4*x2+1.9*x3+0.45*x4+0.95*x5+1.45*x6-0.05*x7+0.45*x8+0.95*x9
-0.4*x1+0.6*x2+0.6*x3>=0;
-0.2*x1-0.2*x2+0.8*x3>=0;
-0.8*x4+0.15*x5+0.15*x6>=0;
-0.6*x4-0.6*x5+0.4*x6>=0;
-0.5*x7-0.5*x8+0.5*x9>=0;
x1+x4+x7