Thx dlhotka for the proposal. This is of course a possible solution, but the performance running Manycam within the virtual machine is horrible.

I do not understand, what is the problem to passthrough a virtual device. A virtual device will be registered as a device and if this device would be only passed through to guest operating system it should not be a big deal.

VMware Fusion Pro on HighSierra on an iMac worked perfect.

I will do some more testing with other OS'es in order to see, if it is a general problem of VMware... Also the other way around (Host Windows, OS Windows)

Nevertheless thank you for the confirmation.

@VMware colleagues: You should really think on supporting virtual devices.