We have just released OpenSolver 2.8.4 which fixes a bug in the 2.8.3 release that caused it to crash on the newest versions of Excel (in most cases the Office 365 versions). This release also fixes a bug where the saved solver choice could get corrupted and force you to re-select the solver.
You can download the 2.8.4 release here.
Don’t forget to enable the update checker in OpenSolver if you want to be notified automatically of new updates like this one.
As always, please let us know if you have any feedback or problems.