I have Multiplicity 4 Pro for a few months, bought on Steam, and it works just fine.
Today I purchased a subscription for Object Desktop (to use Groupy and Fences), and after installing the Object Desktop downloader, my Multiplicity 4 installation reverted to the non-Pro version.
I had to remove the downloader app, uninstall Multiplicity, purge it (with a batch script), and reinstall it fresh to make it work again.
Any tips to make my Object Desktop recognize the Pro version?