The current version of the forum software has reached it's EOL (End Of Life) and support for it will no longer be available after January 2017. The decision has been made that the best course of action is to upgrade to the latest version (it is more secure and has many nice new features, while maintaining a familiar interface, for the members.)
I will attempt to keep the downtime to the least disruptive periods of time based on typical member usage of the site.