The only thing I can think of is that recently iVIBRATE was updated to .NET 4, so if your PC is on the older side and it was working before it could be that. if you go to this Microsoft page and select "Download .NET Framework 4.8 Runtime" and install that, that might fix it. If you already have it installed, it will tell you and you won't be able to install it.
Unfortunately Itch.io doesn't have a great way of being able to offer older versions and would make purchasing/playing iVIBRATE confusing if there were over 50 versions you could download. In saying that, if you bought iVIBRATE you will have received a Steam key, the Steam version of iVIBRATE has all the previous versions of iVIBRATE that have been released. So with the Steam version you can rollback to older versions.
It's really strange that it was working and now it isn't; so the .NET 4 is the only thing I can think of as to why it isn't anymore. Rolling back to an older version via Steam is probably your best bet but I am happy to try and continue to get the latest version working for you.