VirtualBox is already locked by a session (or being locked or unlocked

昨天要幫VM Server 增加記憶體後，不料其中一台VM Guest 卻無法啟動，啟動的訊息
VBoxHeadless: error: The machine 'tvap36' is already locked for a session (or being unlocked)
VBoxHeadless: error: Details: code VBOX_E_INVALID_OBJECT_STATE (0x80bb0007), component MachineWrap, interface IMachine, callee nsISupports
VBoxHeadless: error: Context: "LockMachine(session, LockType_VM)" at line 947 of file VBoxHeadless.cpp

VM Guest 主機名稱 tvap36

VBoxManage startvm tvap36  --type emergencystop 

然後再啟動VM就可以了

參考文章:

http://uzigood.blogspot.com/2016/12/virtualbox-is-already-locked-by-session.html