开着idea，死机了，关机重启。重启之后，重新打开idea报错java.lang.AssertionError:upexpected content storage modification。
goole得到：
If you cannot even open your project in IntelliJ:
Close IntelliJ
Go to the directory <your_home>/.IntelliJIdeaXX/system/cache where XX is your IntelliJ version
Remove all the files in the cache directory.
Then restart IntelliJ
This has worked for me in the past.
于是，C:\Users\yineng\.IntelliJIdea14\system\caches 下的文件全删，启动idea，ok!!!