Cannot find the declaration of element 'jdoconfig' when using JDO/JPA 使用 JPA/JPO 時出現錯誤

Issue: when you  using JPA/JPO, Eclipse display error:
問題: 在 Eclipse 使用 JPA/JPO 時，出現錯誤:

"Description Resource Path Location Type
cvc-elt.1: Cannot find the declaration of element 'jdoconfig'."

Referenced file contains errors (http://java.sun.com/xml/ns/jdo/jdoconfig).  For more information, right click on the message in the Problems View and select "Show Details..."   

launch VirtualBox with error "Failed to create virtual COM object" 執行 VirtualBox 出現錯誤 "建立 VirtualBox COM 物件時失敗"

Issue: when you  launch VirtualBox ,it  fail with error window " Failed to create virtual COM object.... Callee RC: TYPE_E_ELEMENTNOTFOUND (0x8002802B)"

問題: 執行 VirtualBox 時，出現錯誤: 建立 VirtualBox COM 物件時失敗... 被呼叫端 RC: TYPE_E_ELEMENTNOTFOUND (0x8002802B)"