Flexera Software (who acquired Secunia in 2015) have announced that the Secunia PSI (Personal Software Inspector) will be retired on April 20, 2018, at which time it is recommended that it be uninstalled.
Martin Brinkmann has a detailed discussion and list of alternative applications at https://www.ghacks.net/2018/03/11/secunia-retires-personal-software-inspector-psi/ .