We have just uploaded OpenSolver 2.8.1, available here.
This fixes two bugs with the 2.8.0 release. Some users may have encountered an “Automation Error” depending on their version of Excel, which we have now fixed. Additionally we have fixed an error that occurred when cancelling the “Set QuickSolve Parameters” dialog.
As always, please send us any feedback and let us know if you have any problems.