VMware Fusion - Professional Version 8.5.10
VMware Fusion 8.x is not supported on macOS 10.13.x High Sierra, he needs version 10.x or newer (no v9.x exists, because this release was called 8.5.x - and was a free upgrade).

You can have a look here: https://kb.vmware.com/s/article/2088571 

It could very well be that High Sierra became more strict about how an app should be built (no mix between 32-bit and 64-bit ??) - but still pure 32-bit would be okay, and of course pure 64-bit would also work. But it is only my guess.