Fortunately there's a relatively easy workaround for getting the security software functioning again
Many Windows boffins, present company most certainly included, recommend Secunia PSI
for keeping track of the latest updates to Windows application programs. Unfortunately, the latest version -- Secunia PSI 220.127.116.1113 -- doesn't work with Windows 8.1. You should be able to solve the problem by installing an earlier version of PSI, although Secunia itself hasn't endorsed the fallback.