I'm trying to install VirtualBox 4.1.2 on an Intel Core 2 Duo MBPro running 10.5.8
After mounting the image and opening the .mpkg file I get the following error:
Running VirtualBox VM's detected!
The installer has detected running Virtual Machines. Please shutdown all running VirtualBox machines and then restart the installation.
I've never installed VirtualBox on this machine before. Can't find any references to this online anywhere.
This also happened to me on a Mac Mini under 10.5.8. Tried everything, including running the uninstall script, then deleting all Library and ~Library references to VirtualBox, but no luck. Reinstalled 4.1.18, and I'm back in business now, but it looks like the 4.1.20 installer has a problem.
Not sure which download site you're looking at. On my copy of https://www.virtualbox.org/wiki/Downloads there's a big fat text saying "VirtualBox older builds" with a link to the old versions.