I’ve got the different error: it looks for file Dose fo Excel.dll within download folder, which is Application Files\Dose for Excel_3_1_7_5, and there is no such a file in that folder, so no wonder it throws an error. There is only one file in that folder, Dose for Excel.vsto, and that same file is also in root folder, too.
So, something is dodgy with installation, which is pitty, as program features sound very nice. Hope they will see these complaints and fix it!