A recently discovered bug in Apple's OS X Mountain Lion causes most applications to crash if the user simply types in an eight character string of characters. The rather ironic part of this particular bug is that it also causes the Mac error reporter to crash too.
A posting a few days ago by developers on the site Open Radar, show that simply typing in the string of characters "File:///" will cause most applications to crash. The bug only seems to be in Apple's Mountain Lion version of OS X (including the beta version) and does not have the same effect on either Lion or Snow Leopard.
It seems that the culprit is in the way the OS uses Data Dectectors to automatically recognize dates, contact information and locations. When the software passes the string to the data detectors to extract a URL, the system throws as assertion and the application crashes. The crash does not happen on applications that do not use the data detectors.
While your waiting for a fix to the problem, you can take a look at this delightful picture from the Apple Maps fiasco, as picking on them for that never gets old.