Credit for the fix – https://www.tweaking4all.com/forum/applemac-hardware/macos-fix-vmware-fusion-version-mismatch-with-vmmon-module/
1. Close VMware Fusion
2. Open the Terminal and execute:
sudo rm -rf /System/Library/Extensions/vmmon.kext sudo cp -pR /Applications/VMware\ Fusion.app/Contents/Library/kexts/vmmon.kext /System/Library/Extensions/ sudo kextutil /System/Library/Extensions/vmmon.kext
3. Exit Terminal and open Fusion again.
Now … you may run into an error message with the last command.
In that case you can try the following command, or like I had to do: reboot your Mac and try that last command again;
sudo kextunload /System/Library/Extensions/vmmon.kextd