Document is empty.
Location: '/home/ron/VirtualBox VMs/Semios Win7 /Semios Win7 .vbox', line 1 (0), column 1.
/home/vbox/vbox-5.0.12/src/VBox/Main/src-server/MachineImpl.cpp[740] (nsresult Machine::i_registeredInit()).
Result Code:
NS_ERROR_FAILURE (0x80004005)
Component:
MachineWrap
Interface:
IMachine {f30138d4-e5e

解决方法: 编辑清空 .vbox里的内容, 把 .vbox-prev 里的内容复制过去,保存刷新重新启动

Go to the location where you store your VM /home/ron/VirtualBox VMs/Semios Win7 /.

Open .vbox in your favorite text editor to check if it is empty. Probably it is :) In the same folder you should have file Semios Win7 .vbox-prev. Copy the contents of this file to Semios Win7.vbox, save, and try again.

Now it should work. I did the same and it worked for me.