VMWare Fusion: /dev/vmmon konnte nicht geöffnet werden

On my MacBook Pro I have VMWare Fusion with Windows 10 installed. It worked quite well until I started getting following error message:

 

/dev/vmmon konnte nicht geöffnet werden: Es existiert keine Datei und kein Ordner dieser Art. Stellen Sie sicher dass das Kernelmodul “vmmon” geladen ist.

It is the same as the the english variant

Could not open /dev/vmmon: No such file or directory.

First, I thought it could be an error after upgrading the MAC OS from Yosemite to Mavericks. However, it turned out to be a conflict with Oracle’s VirtualBox, known as Oracle VM VirtualBox. VirtualBox is a free software for running virtual machines, i.e. same purpose as VMWare. I didn’t realize, that it was installed on my MAC. It might came with some other Apps, that were previously installed. Like Android emulator “Andy” or some other.

So how to fix the issue? Just uninstall VirtualBox. Follow the steps below:

The system restart is not required, your VMWare Fusion should work from now on properly. If you need VirtualBox in the future for other apps, you can install it again from Oracle’s website.