Screenshot Error in Mac OS X 10.8, Short key working but no file generated
Today I'm going to use the mac screenshot (screen capture from COMMAND+CONTROL+SHIFT+4) to capture the window while the problem comes. The short key is working and the icon of pointer has changed accordingly, but once I clicked there is no file generated in the destination folder. I would like to know what's wrong with my screenshot? Is there anyone who encountered the similar errors before?
I'm using Mac OS X 10.8.5 and I believe the screenshot is still avalaible after the update from the 10.7.x. I guess the problem is more about the screenshot applet rather than the system. Besides, I'm eager to know that is there any method to solve this problem.
Thank you.
MacBook Pro, OS X Mountain Lion (10.8.5)