Microsoft has released a hotfix for Skype which addresses two known issues in the Windows version of the software. The hotfix addresses a crash during a Skype IM session, as well as file sending bugs.
The hotfix addresses these two issues: Instant Messaging – Skype client crashes during a Skype IM session, which may in some cases result in the last IM entered or sent prior to the crash being delivered to a different IM contact after the Skype client is rebooted or logged in as a new user.
Wow Microsoft, are you serious?
The instant messaging issue seems to be for Windows only, as those on Android or iOS are not affected. So make sure to update your Skype client as soon as possible.