Xpress patch 8.0.8 is now available on Box for Windows 64 and 32, Linux 64 and Mac 64 from
Xpress-Optimizer 29.01.14 release notes:
* Improved behavior of the barrier algorithm to handle problems with large bounds.
* Fixed an issue with MIP presolving that could result in incorrect solutions being returned.
* Fixed an issue with presolve eliminations of variables with quadratic cost that could result in a non-optimal solution being returned.
* A starting MIP solution loaded with XPRSloadmipsol that is dropped due to being cut off should now be reported as such instead of 'infeasible'.
* Fixed an issue with the presolving of user supplied MIP solutions that could result in a worse solution being passed to the Optimizer.
* Fixed an issue with very large mixed integer Gomory cuts that could result in a callstack overflow.
* Fixed a potential deadlock when solving a MIP with indicator constraints.
* Improved values returned by XPRSstrongbranch on numerically hard problems.
* Fixed an issue with the Python interface that returns an error on getVariable(), getConstraint(), getSOS() when the problem has no variable, constraint, or SOS, respectively.
* Fixed an issue with the Python interface that might trigger an error when retrieving a variable/constraint/sos from a problem.
* Fixed an issue with the Python interface that prevented getobj() from working correctly.
* Fixed an issue with the Python interface where multiplying linear expressions yields an incorrect quadratic expression.
* Fixed an issue with the Python interface where requesting more elements of a quadratic constraint or objective function than actually present might result in incorrect data returned.
* Fixed an issue with the Python interface that occurs when using getControl() or getAttrib() with an iterable object as a parameter.
* Fixed an issue with the Python interface whereby passing generators as arguments of API function might yield an incorrect result.
* Fixed an issue with the Python interface where the Dot product over arrays of many dimensions might return an incorrect result.
* Fixed an issue with the Python interface where indices of constraints or values of their slacks might be returned incorrect.
Xpress-Nonlinear 29.01.14 release notes:
* Setting XSLP_DELTAZLIMIT to a negative value will now prevent all perturbation attempts to numerical derivatives.
* Fixed an issue with the SLP-MIP-SLP heuristics for problems where the last MIP node is LP feasible.
* Fixed a problem in which XSLPfixpenalties would integer presolve the problem if there are global entities loaded.
* XPRSloaddirs and XSLPreaddirs can now also be used after calling XSLPconstruct.
This is the latest Xpress update for the Xpress 8.0 release branch. Please note that it must be installed over a prior installation of FICO Xpress 8.0 and requires a valid Xpress 8.0 license.