Even in the CD-i Community there is not a lot of experience with Mame CD-i Emulator. There is an open bug since version 0.222 and it appears older versions offer more compatibility compared to the most recent version. On top of that, it is not exactly user friendly. It's a bit complicated to set up. CD-i member TwBurn about this: "It's not exactly user friendly. One would expect you point it to a bios file and rom image and that would be it, but it's quite complicated." CD-i member Retrostuff shares a valuable tip: "It helps if you are familiar with the MESS/MAME Software Lists concept. Make sure that the rompath in the mame.ini points to all directories that you store the ROMs and Software List CHDs in. The rest is about selecting the correct machine (e.g. "CD-i (Mono-I) (PAL)" and not "CD-i (Mono-I) (PAL) BIOS") in the GUI, then a software (e.g. "Tetris (Euro, USA") and a BIOS (e.g. "Philips CD-i 220 F2"). The rest is to have patience and wait at the screen (see above) for a minute or so."
[Thanks, Retrostuff, TwBurn]