The following error message:
Is most often indicative of the incorrect "bit version" of the Analytic Solver Platform being installed.
It is recommend that you uninstall the Analytic Solver Platform at this point in order to perform a reinstall of the correct "bit version".
Please follow the steps available here to uninstall.
Once this is complete, please contact email@example.com and let us know your current "bit version" of Excel so that we may supply you with the correct next steps. To find out what "bit version" of Excel you are running, please go here.
Some extra details:
If you select No at the above dialog, Excel should open normally but you will not see the Analytic Solver tabs within Excel. This is okay, as the Analytic Solver COM add-in can not load properly unless the installed bit version matches you Office/Excel bit version. It is recommended you do not attempt to load the add-in after receiving the above error message to avoid unnecessary confusion.
If you select Yes, a workbook will open and you will see something similar to this:
This is the expected behavior, closing this workbook will not disable the add-in. Next time you open Excel, you will likely receive the error message depicted near the beginning of this article again if you have not yet gone through the uninstall and reinstall steps above.