I'm not sure what sort of 'ailty' covers this. Patch-ality? Wipe-ality? I don't know where I'm going with this but the main thing is that a patch meant to fix Mortal Kombat X's PC issues has done so but at the cost of wiping any save data.
It's doubly galling as "save data safety check to try to eliminate save data loss" was one of the 30+ fixes the update was meant to introduce.
This quote from the many Steam comments on the problem perfectly frames the semi-tragedy of the whole thing:
While the console versions of Mortal Kombat X enjoyed a largely flawless experience, the PC port (handled by High Voltage) suffered from a long list of problems, including poor frame rate, glitches and bugs throughout. The original patch contained 15GB of fixes.
The save-killing update was quickly pulled, with High Voltage saying it was looking into the causes and testing 'a fix' for a new patch. The last comment on the Steam page from the studio today states: "We continue to work on the fix for Save Data Loss. In order to ensure it is properly tested, we will look to post the fix early tomorrow. Again, we thank you for your patience and your input".