Stuck unable to change mode from pro to lite

So I got the install, accidentally installed the pro version and the evaluation ran out, I realized later I actually bought the key for the lite version. Now when I try to select to switch to the lite version I can't do so. I have already attempted to uninstall/install and same issue.

Win10, 64bit.

If you have purchased a key for Light, you just need to load that key into Help > Licence Manager and Opus will switch into Light mode.

If the key is downloaded as a .opuscert file, you should also be able to double-click it to do the same.