When solving a simple assignment problem in Maple 2015.1 the bug occurs:

In Maple 2012 there are no problems:

**A := Matrix([[1, 7, 1, 3], [1, 6, 4, 6], [17, 1, 5, 1], [1, 6, 10, 4]]): **

**n:=4: **

**z:=add(add(A[i,j]*x[i,j], j=1..n), i=1..n): **

**restr:={seq(add(x[i,j], i=1..n)=1, j=1..n),seq(add(x[i,j], j=1..n)=1, i=1..n)}; **

**sol:=Optimization[LPSolve](z, restr, assume=binary); **