You should also probably try and see if the same thing happens in a VM. The flash drive might be failing and I don’t think Void does CRC checks of files when copying them… definitely not when funning them, like the installer for example.
EDIT: I remember the installer bringing me back to the partitioning setup, but that’s because I partition manually, not through the Void installer, so the installer thinks that that step is skipped. No worries though, just go to the end of the installer setup and continue with the provided settings. If an adequate target partition has been set, it will install Void.