It has come to my attention that iiMii Maker (Specifically the one on my Patreon but it's possible it effects Itch.io-downloaded iiMii Maker as well) on Windows 11 has a chance to come in an improper state.
The modelcustomization file (iiMii Maker_Data/models/modelcustomization) can sometimes be downloaded and a .bin extension can be appended to the file name automatically. modelcustomization file should NOT have any extension. If you open iiMii Maker and it says to add custom models or, worse yet, has missing/improper models then ensure both that the file exists and it does not have any extension.
Please note that this testing was very irregular. I do not own Windows 11 and will have problems helping people get it started using this operating system in any ways that it may differ from Windows 10, which iiMii Maker was designed on and for. If people would like to test Windows 11 functionality then please feelr more than welcome to do so.