如何修复在尝试打开Android XML文件时出现的nullpointerexception ?

Since I updated the ADT plugin to v1.21 in Eclipse, I can no longer easily open any XML layout files in my Android project. As soon as, I click on the file, It throws NullPointerException. Here are the stack traces from the error log:Since I updated the ADT plugin to v1.21 in Ecli