When running Visual Studio Express 2013 in Windows 8.1 in VirtualBox on Mac OS X, you may find that widgets are not appearing in the designer.
Widgets not appearing:
This seems to be due to a bug in the VirtualBox's video driver. In order to resolve this, first the VM you are using must not currently be running. Go to your Oracle VM VirtualBox Manager, select the VM you are using and then press Settings. Select the Display tab. In Video -> Extended Features, uncheck Enable 3D Acceleration.
Widgets now appear: