Skype menu "Tools" says: "Export chat history from Skype 7.x..." Once the chat history is exported, it is no longer possible to search for a text string in more than 10 years of chat history.
A Skype update may be required
Your conversation history will still be available on your device after you update.
Also, the latest iOS version of Skype still does not support Screen sharing which has been in place for more than 10 years on other platforms.
The following features are not currently supported:
