As a workaround I manually downloaded the ext-pack here: https://download.virtualbox.org/virtualbox/5.2.10/Oracle_VM_VirtualBox_Extension_Pack-5.2.10.vbox-extpack and then in VirtualBox: File -> Preferences -> Extensions -> Adds new package ("+" Button)
As a workaround I manually downloaded the ext-pack here: https:/ /download. virtualbox. org/virtualbox/ 5.2.10/ Oracle_ VM_VirtualBox_ Extension_ Pack-5. 2.10.vbox- extpack
and then in VirtualBox:
File -> Preferences -> Extensions -> Adds new package ("+" Button)