Microsoft released Windows 10 Build 10576 for PCs few days back for Windows Insiders in fast ring. After upgrading to the Build 10576, all of the Skype messages and contacts are gone in the Messaging app. This is one of the issue faced by the users and Microsoft has provided workaround for this issue.
- Open file explorer and navigate to this folder :
- Delete or rename the “PrivateTransportId” file. (If the ‘file name extension’ option is ticked, you’ll see this file as “PrivateTransportId.setting” )
- Restart the Messaging app.
Hope this solve the issue.