Yesterday Skype released updates for the above mentioned operating systems to fix an issue that would cause Skype to crash when receiving a specific set of 8 characters within a message. Skype for Mac OS X and the Windows Store Skype app were not affected by this issue. Further details on this issue are available in this article. The updates can be downloaded from here if you are not prompted by Skype to install an update.
Installations of updates for Skype generally go smoothly. However as always, I would recommend backing up the data on any device for which you are installing updates in order to prevent data loss in the rare event that any update causes unexpected issues.