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If none of the above solve the problem, make sure you are running the latest version of VirtualBox for your machine. Older versions of VirtualBox do not support VT-x on newer computers.
Network is not working
In some cases, it may not be possible to use the VM to connect to the outside, or connections only work to the local network. This may be due to proxies on your local network intercepting external traffic.
To solve this, configure the VM with your local network proxy settings in Yast2 > Network settings > Proxy.
Drag'n'Drop not working
Check that the Settings for the VM are set to 'Bidirectional'. Also, when the VM is running, check that the menu option "Devices" -> "Drag'n'Drop" is also set to Bidirectional.
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