Pandacoin had a major upgrade and a required network swap on May 17, 1PM (UTC + 2) in order to modernise the project, and step away from the limitations that Pandacoin faced under its previous codebase.
New mandatory update available now. See http://cryptodepot.org/mandatory-pandacoin-upgrade/
Learn about Pandacoin here : http://cryptodepot.org/currencies/pandacoin/
Check out the Pandacoin blog here https://medium.com/@Pandacoin_PND