When I start Parallels Desktop for Mac on macOS High Sierra I get the following warning:
System Extension Blocked. A program tried to load a new system extension signed by "Parallels International GmbH" and it was blocked. If you want to enable extensions from this developer, go to the Security & Privacy System Preferences pane.
macOS High Sierra 10.13 introduces a new feature that requires user approval before loading newly-installed third-party kernel extensions. Third-party kernel extensions (KEXTs) that were already present when upgrading to macOS High Sierra are granted automatic approval.
This approval UI is only present in the Security & Privacy preferences pane for 30 minutes after the alert. Until the user approves the KEXT, future load attempts will cause the approval UI to reappear but will not trigger another user alert.
For more information please refer to the Apple's official tech note: Technical Note TN2459.
Open System Preferences > Security & Privacy > General > click Allow next to the corresponding message:
If pressing Allow button using the mouse doesn't give any positive results, use the steps described below:
- Open System Preferences > Security & Privacy > Keyboard > Shortcuts and switch Full Keyboard Access to All controls.
- Now open System Preferences > Security & Privacy > General.
- Press Tab key om the keyboard until the Allow button is highlighted, then hit Spacebar on the keyboard to press Allow button.
- Close System Preferences window and start Parallels Desktop.
Why Parallels Desktop needs its own kernel extensions?
To deliver all Parallels Desktop features, such as virtualization, USB and Network, Parallels Desktop loads the following kernel extensions to macOS:
com.parallels.kext.hypervisor - a proprietary core virtualization driver, which makes Parallels Desktop the best virtualization solution for Mac.
com.parallels.kext.vnic - Shared Network driver, which is used by a virtual router who manages all network services for a VM, such as gateway,DNS, DHCP, port forwarding, network conditioner etc.
com.parallels.kext.usbconnect - USB driver, loaded when a USB device connects to a virtual machine (VM). Supports all USB data transfer protocols except of isochronous transfer.
com.parallels.kext.netbridge - Bridged Network driver, creates a virtual network adapter on Mac to connect a VM to Mac's subnet directly.