The Xpress-Optimizer and Xpress-SLP patch 28.01.09 for Xpress 7.9 is now available for Linux and Windows from here.
Xpress-Optimizer release notes:
* Fixed an issue with the XPRSgetdualray function that could return an incorrect ray.
* Improved sparse matrix ordering in the barrier algorithm on very large problems.
* Fixed an issue in presolve for symmetric problems.
* Fixed an issue related to heuristics that had the potential to cause a crash.
Xpress-SLP release notes:
* No changes since version 28.01.07.
This is the latest Xpress-Optimizer and Xpress-SLP patch for the Xpress 7.9 release branch. Please note that it must be installed over a prior installation of Xpress 7.9 and requires a valid Xpress 7.9 license.