Just tried it on my 2012 mac with Fusion Player 12.1.2 the other day. Windows 98 does no longer boot. Worked fine on Fusion 8. My guess is that it needs Binary Translation support and that's not available with 12.x
edit:
My bad.
Figured to see if I could find out why. Upgrading from virtual hardware 4 to virtual hardware 6 seems to help. (yeah yeah, it's an old VM)
edit 2:
With some of the more recent AMD processors however you are out of luck, they really need BT.
It would be nice if Win98 works for everyone still.
The background information for that reason is contained in these two detailed articles:
https://blog.stuffedcow.net/2015/08/pagewalk-coherence/
https://blog.stuffedcow.net/2015/08/win9x-tlb-invalidation-b...
tl;dr: newer AMD processors have non-coherent pagewalks. Intel has maintained coherent pagewalks despite that not being explicitly guaranteed in their documentation. Win9x depends on that.
I will say ME runs fine where 98 doesn't. weird!
Caching/speculative execution related bugs are very sensitive to patterns of memory access.
https://communities.vmware.com/t5/VMware-Workstation-Pro/Win...
regsvr32 %WINDIR%\AppPatch\slayerui.dll
Set up binary compatibility for any exe as you would do in XP. Problem solved.