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2020-12-14 22:19:43
The MIP best bound is infinite because no feasible integer solution exists.
Indeed, all the variables in your ILP have been restricted to general integer values (Generals section).
Here an example by using GLPK to solve the ILP.
15 rows, 10 columns, 25 non-zeros
10 integer variables, none of which are binary
...
Solving LP relaxation...
GLPK Simplex Optimizer, v4.65
5 rows, 10 columns, 15 non-zeros
0: obj = -8.000000000e+00 inf = 1.631e+01 (5)
5: obj = -3.750000000e-01 inf = 0.000e+00 (0)
* 8: obj = 3.000000000e+00 inf = 0.000e+00 (0)
OPTIMAL LP SOLUTION FOUND
Integer optimization begins...
Long-step dual simplex will be used
+ 8: mip = not found yet <= +inf (1; 0)
+ 8: mip = not found yet <= tree is empty (0; 3)
PROBLEM HAS NO INTEGER FEASIBLE SOLUTION
Time used: 0.0 secs
Memory used: 0.1 Mb (63069 bytes)