I followed the instruction from here: https://support.skype.com/en/faq/FA829/How-can-I-r
This should resolve the I/O error:
Make sure that Skype is actually not running on your PC (Quit or kill using Task Manager).
Go to Windows Start and in the Search/Run box type %appdata%\skype and press Enter or OK button. Go trough the whole Skype folder (including subfolders) and delete any files starting with “temp-“ or ending with “-journal” or with extension .lock.
The best way to have several accounts running at the same time on one computer is to start all accounts using shortcuts with the /secondary switch.