Vmware Fusion And Big Sur

VM Tools – Even though Big Sur to works on Parallels and Fusion, do not install VM tools yet. Some reports say that after installing VM tools the system boots fine YMMV. Parallels Tools – VM can get stuck on a black screen after the reboot. Would recommend not installing the tools. Ready for macOS Big Sur. Run nearly any operating system on macOS 11 Big Sur without rebooting. Fusion now has added support for operating entirely without Kernel Extensions on Big Sur, making it more secure and ready for the future of macOS, all while continuing to perform on macOS 10.15 Catalina.

As many people are slowly upgrading to the latest MacOS version, Big Sur, there are a few of us who are running into some compatibility issues. For me the only one that has given me some grief is VMWare Fusion. Many in my industry run multiple VMs to be able to connect to various customer or just to be able to use some of the Cisco tools which do not support any other operation system other than Cisco. There are two issues which I needed to fix in order to get one of my VMs back. First, the error below “VMware Fusion does not support virtualized performance counters on this host.” This error prevented the VM from booting up.

This can be resolved by going to Settings > Processor & Memory > Advanced options and unchecking “Enable code profiling applications…”

VMware Fusion Processor & Memory Settings

The second error was “You are running this virtual machine with side channel mitigations enabled.” This error could be ignored and didn’t seem to affect the VM at all, but it was still annoying. This kb had all I needed to get that message out of the way.


Recently updated to macOS Big Sur. I’m not sure why I do this sort of thing quite so freely… I always naively assume everything will be OK. And so far, Big Sur vs Catalina is just a bit nightmare.

I’m sure there’s a huge amount of “don’t like change” in there but there are many things that are annoying the crap out of me with Big Sur. Calendar notifications for one. Gah.

But anyway, one real issue I have had was with VMware Fusion. I was previously on v11.something and when trying to launch a VM got greeted with “Host OS does not have enough physical memory to launch this VM” which was a complete load of bollocks. After a quick Google, it was evident it was a VMware incompatibility issue – Fusion 11 will not run on Big Sur and you must upgrade to VMWare 12. Yay. $100 later and I have Fusion 12 and… things are still broken. Main issue is that trying to start a VM results in a bunch of error messages… these seem to get resolved by changing the compatibility level of the VM…. but even then, starting the VM ends up in a black screen.

There was a very similar issue when Catalina came out, and this was caused by new Security / Privacy controls around Screen Recording. This was fixed usually either by a filthy hack; or the proper way which is by allowing VMware Fusion to Screen Record through the System Prefs. However, on this occasion, that was all fine.

I’ve found nothing yet that specifically relates to VMWare Fusion on macOS Big Sur and a black screen on the VM. However, I did find an *old* tip that was worth a go… and for me, at least, it only bloody worked. (I think. Can’t be sure.) I’m on a 27″ iMac Pro but editing the VMX file worked.


In the VMWare library, click your VM and make sure it is shut down.

Vmware Fusion And Big Sur

Then right-click and hit show in Finder.

Vmware Fusion And Big Sur

Right click the VM file and click ‘Show Package Contents’

Look for the VMX file

Vmware Fusion Big Sur Not Enough Physical Memory

Right click and open in TextEdit. Civilization 6 online.


Vmware Fusion 11 And Big Sur

and change to

Save in TextEdit and quit.

Now start the VM. It *might* work.