CPXERR_BAD_PIVOT
1267 Illegal pivot
#define CPXERR_BAD_PIVOT 1267
This error occurs if illegal or bad
simplex pivots are attempted. Examples
are attempts to remove nonbasic variables
from the basis or selection of a zero column
to enter the basis. Also, this error code
may be generated if a pivot would yield a
numerically unstable or singular basis.