Hello. When working with PROC OPTMODEL and PROC IML, we're actually working with a solver. Between versions of SAS, this solver is constantly changed for various reasons. When the solver is updated, a problem that works fine with the current version of SAS then no longer works with the new version. Since this is for multiple clients, it is not possible to optimize the solver and please everyone. Would it be possible to add a new option to the PROCS so that when we invoke them, we pick which solver we want to be using? This way, if someone wants a solver optimized, then a new solver would be shipped and they could use it while it would leave all other users stable as they could keep using the solver they were using before. This of course means that SAS needs to ship several solvers but I'm sure it can be done.