@shakalakka - there are times whereby controller adapters will not get detected properly, especially when you have adapters that aim to work with more than one targeted input device - exempli gratia: a Sony PlayStation 1/2 controller adapter that aims to work with the Sony PlayStation 3 and PC - in which I have two of those myself, with one of them being a GameWare-branded (Game UK) adapter that works well with the PS3, and can either work as a DirectInput adapter, or as a SCPToolkit-compatible “PLAYSTATION3® Controller” (that’s the device name), and the other one being a Logic3-branded adapter, which is blacklisted by Sony in the newer PS3 firmware versions, but apart from that, works in the same way as the former adapter.
From my experience, SCPToolkit works with RetroArch for native PS3/PS4 gamepads, and PS1/PS2 controller adapters that are detected as a SCPToolkit-compatible “PLAYSTATION3® Controller”, but as adapters with such features are hard to find nowadays, I would personally advise against using/buying adapters altogether if you want a near-perfect/almost hassle-free game input device setup in this day and age on Microsoft Windows.