Parallels Desktop cannot be started: Unable to start Parallels services.
Cause
Parallels Desktop cannot connect to one of the required services.
There has been an authentication failure of system kernel extensions.
Parallels Desktop cannot access system kernel extensions.
macOS® operating system doesn't allow Parallels Desktop kernel extensions to load due to system policy.
Most often the behavior is caused by a macOS® misconfiguration causing incorrect folder permissions resulting in access errors.
Troubleshooting and Solution
Note: The behavior has mostly been fixed in macOS® Big Sur and above. Therefore, as the very first step, it is advised to update macOS®, as described here. If it is not an option, the steps below may help fix it.
As a first troubleshooting step, please open Terminal (Applications > Utilities > Terminal) and execute the following command:
ls -Ol /private/var/db/ | grep 'restricted'
Check the command output, and if the resulting list is missing KernelExtensionManagementfolder, then perform the following steps:
Restart your Mac into macOS Recovery. To do so, restart your Mac and hold down Command+R on the keyboard until the Apple logo appears on the screen. Note: If you see a login window instead of the Utilities window, it's possible that you didn't press Command+R early enough. Restart your Mac and try again.
Once in Recovery, open Disk Utility and note the name of your Mac's main drive. By default, it's Macintosh HD.
CloseDisk Utilityand from the top menu bar click Utilities > Terminal.
Please note that if your Mac's drive is called anything other than Macintosh HD, you need to adjust the command accordingly.
Restart your Mac by clicking Apple logo > Restart...
Advanced troubleshooting
Start Terminal: open Finder - Applications - Utilities - Terminal.
Execute the following command:
sudo kextcache --clear-staging
Note: You will need to enter your Mac password to run the command. No symbols will be shown due to security measures, so just hit the keys and use return/Enter.
Try starting Parallels Desktop. If the issue still persists, execute the next command:
sudo touch /System/Library/Extensions
Note: You will need to enter your Mac password to run the command. No symbols will be shown due to security measures, so just hit the keys and use return/Enter.
Restart the Mac and try launching Parallels Desktop.
If the issue still persists, restart your Mac into macOS Recovery. To do so, restart your Mac and hold down Command+R on the keyboard until the Apple logo appears on the screen. Note: If you see a login window instead of the Utilities window, it's possible that you didn't press Command+R early enough. Restart your Mac and try again.
From the top menu bar select Utilities and then Terminal.
Execute the following command (keep in mind that all letters in the last part must be in the upper case, otherwise, the command won't work):
spctl kext-consent add 4C6364ACXT
Note: Hit return/Enter after entering the command to execute it.
The result of performing this command should look like the below image:
To restart Mac into normal mode execute the command reboot or select Apple logo > Restart...
Try launching Parallels Desktop again.
If none of the steps above have helped, the only solution left is to reinstall macOS® from Recovery to update system files as per instructions from the article. By reinstalling macOS® from Recovery, only system files will be updated, keeping personal files and installed applications intact.
Using MDM for deployment of Parallels Desktop
In case you install Parallels Desktop in Enterprise environment, disable MDM or check its settings. It may block extension installation if certain settings are enabled for Manageable profile.
