El Capitan vs Mojave and High Sierra

[levmc]

Mojave has problems with virtual machines (Fusion and Virtualbox) and High Sierra has bluetooth disconnecting problems.

Would that make El Capitan the best? What about Sierra?

 

[chrfr]

Mojave has problems with virtual machines (Fusion and Virtualbox)

Could you explain the problems? I use Mojave in a Fusion virtual machine with some frequency and don't notice any specific problems.

 

[levmc]

It says "broken pipe" and this "Please make sure that the kernel module `vmmon' is loaded." whenever I try to start vmware fusion.

 

[chrfr]

It says "broken pipe" and this "Please make sure that the kernel module `vmmon' is loaded." whenever I try to start vmware fusion.

You need to be sure you've allowed the extensions in the Security and Privacy System Preference on both the host and guest Mac.
If the problem continues, delete VMware Fusion and reinstall it.
These issues would be specific to Fusion, not Virtualbox.