Jsut upgrade to v4. It has been a nightmare going on three hours now. Networking worked at first. Then I restarted the Mac and now I just keep getting this message. I have done what it says to no avail. Failed to open the Parallels networking module. Your virtual machine will continue to work normally, but the networking will be disabled. You can fix the problem by restoring the default network settings. To this effect, go to Parallels Desktop > Preferences > Network and click Restore Defaults.